View source for Thrust-to-weight ratio

{{Short description|Dimensionless ratio of thrust to weight of a jet or propeller engine}}
'''Thrust-to-weight ratio''' is a [[dimensionless quantity|dimensionless]] ratio of [[thrust]] to [[weight]] of a [[rocket]], [[jet engine]], [[Propeller (aircraft)|propeller]] engine, or a vehicle propelled by such an engine that is an indicator of the performance of the engine or vehicle.

The instantaneous thrust-to-weight ratio of a vehicle varies continually during operation due to progressive consumption of fuel or [[propellant]] and in some cases a [[gravity gradient]].  The thrust-to-weight ratio based on initial thrust and weight is often published and used as a [[figure of merit]] for quantitative comparison of a vehicle's initial performance.

==Calculation==
The thrust-to-weight ratio is calculated by dividing the thrust (in SI units &ndash; in [[newton (unit)|newton]]s) by the weight (in newtons) of the engine or vehicle. The weight (N) is calculated by multiplying the mass in [[kilogram]]s (kg) by the acceleration due to gravity (m/s{{sup|2}}). The thrust can also be measured in [[Pound (force)|pound-force]] (lbf), provided the weight is measured in pounds (lb). Division using these two values still gives the numerically correct (dimensionless) thrust-to-weight ratio. For valid comparison of the initial thrust-to-weight ratio of two or more engines or vehicles, thrust must be measured under controlled conditions.

Because an aircraft's weight can vary considerably, depending on factors such as munition load, fuel load, cargo weight, or even the weight of the pilot, the thrust-to-weight ratio is also variable and even changes during flight operations. There are several standards for determining the weight of an aircraft used to calculate the thrust-to-weight ratio range.

* '''Empty weight''' - The weight of the aircraft minus fuel, munitions, cargo, and crew.
* '''Combat weight''' - Primarily for determining the performance capabilities of fighter aircraft, it is the weight of the aircraft with full munitions and missiles, half fuel, and no drop tanks or bombs.
* '''Max takeoff weight''' - The weight of the aircraft when fully loaded with the maximum fuel and cargo that it can safely takeoff with.<ref>[https://ntrs.nasa.gov/api/citations/19850010645/downloads/19850010645.pdf?attachment=true NASA Technical Memorandum 86352 - Some Fighter Aircraft Trends]</ref>

==Aircraft==
The thrust-to-weight ratio and [[Lift-to-drag ratio|lift-to-drag]] ratio are the two most important parameters in determining the performance of an aircraft.

The thrust-to-weight ratio varies continually during a flight. Thrust varies with throttle setting, [[airspeed]], [[Altitude#Altitude in aviation|altitude]], air temperature, etc. Weight varies with fuel burn and payload changes. For aircraft, the quoted thrust-to-weight ratio is often the maximum static thrust at sea level divided by the [[maximum takeoff weight]].<ref>John P. Fielding, ''Introduction to Aircraft Design'', Section 3.1 (p.21)</ref> Aircraft with thrust-to-weight ratio greater than 1:1 can pitch straight up and maintain airspeed until performance decreases at higher altitude.<ref name="thedrive20160509">{{Cite web |url=https://www.thedrive.com/the-war-zone/3383/what-it-was-like-flying-and-fighting-the-f-16n-viper-topguns-legendary-hotrod |title=What it's Like to Fly the F-16N Viper, Topgun's Legendary Hotrod |last1=Nickell |first1=Paul |last2=Rogoway |first2=Tyler |date=2016-05-09 |website=The Drive |access-date=2019-10-31 |archive-date=2019-10-31 |archive-url=https://web.archive.org/web/20191031061848/https://www.thedrive.com/the-war-zone/3383/what-it-was-like-flying-and-fighting-the-f-16n-viper-topguns-legendary-hotrod |url-status=live }}</ref>

A plane can take off even if the thrust is less than its weight as, unlike a rocket, the lifting force is produced by lift from the wings, not directly by thrust from the engine. As long as the aircraft can produce enough thrust to travel at a horizontal speed above its stall speed, the wings will produce enough lift to counter the weight of the aircraft.

:<math>\left(\frac{T}{W}\right)_\text{cruise} = \left(\frac{D}{L}\right)_\text{cruise} = \frac{1}{\left(\frac{L}{D}\right)_\text{cruise}}.</math>

===Propeller-driven aircraft===
For propeller-driven aircraft, the thrust-to-weight ratio can be calculated as follows in imperial units:<ref>Daniel P. Raymer, ''Aircraft Design: A Conceptual Approach'', Equations 3.9 and 5.1</ref>
:<math>\frac{T}{W} = \frac{550\eta_\mathrm{p}}{V} \frac{\text{hp}}{W},</math>
where <math>\eta_\mathrm{p}\;</math> is [[propulsive efficiency]] (typically 0.65 for wooden propellers, 0.75 metal fixed pitch and up to 0.85 for constant-speed propellers), hp is the engine's [[shaft horsepower]], and <math>V\;</math>is [[true airspeed]] in feet per second, weight is in lbs.

The metric formula is:
:<math>\frac{T}{W}=\left(\frac{\eta_\mathrm{p}}{V}\right)\left(\frac{P}{W}\right).</math>

==Rockets==
[[File:Thrust to weight ratio vs Isp.png|thumb|upright=1.6|Rocket vehicle thrust-to-weight ratio vs [[specific impulse]] for different propellant technologies]]

The thrust-to-weight ratio of a rocket, or rocket-propelled vehicle, is an indicator of its acceleration expressed in multiples of gravitational acceleration ''g''.<ref name="sutton">George P. Sutton & Oscar Biblarz, ''Rocket Propulsion Elements'' (p. 442, 7th edition) "thrust-to-weight ratio ''F''/''W<sub>g</sub>'' is a dimensionless parameter that is identical to the acceleration of the rocket propulsion system (expressed in multiples of ''g''{{sub|0}}) if it could fly by itself in a gravity-free vacuum"</ref>

Rockets and rocket-propelled vehicles operate in a wide range of gravitational environments, including the ''weightless'' environment. The thrust-to-weight ratio is usually calculated from initial gross weight at sea level on earth<ref>George P. Sutton & Oscar Biblarz, ''Rocket Propulsion Elements'' (p. 442, 7th edition) "The loaded weight ''W<sub>g</sub>'' is the sea-level initial gross weight of propellant and rocket propulsion system hardware."</ref> and is sometimes called ''thrust-to-Earth-weight ratio''.<ref>{{cite web
 |publisher   = The Internet Encyclopedia of Science
 |title       = Thrust-to-Earth-weight ratio
 |url         = http://www.daviddarling.info/encyclopedia/T/thrust-to-Earth-weight_ratio.html
 |access-date  = 2009-02-22
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20080320040846/http://www.daviddarling.info/encyclopedia/T/thrust-to-Earth-weight_ratio.html
 |archive-date = 2008-03-20
}}</ref> The thrust-to-Earth-weight ratio of a rocket or rocket-propelled vehicle is an indicator of its acceleration expressed in multiples of earth's gravitational acceleration, ''g''{{sub|0}}.<ref name="sutton"/>

The thrust-to-weight ratio of a rocket improves as the propellant is burned. With constant thrust, the maximum ratio (maximum acceleration of the vehicle) is achieved just before the propellant is fully consumed. Each rocket has a characteristic thrust-to-weight curve, or acceleration curve, not just a scalar quantity.

The thrust-to-weight ratio of an engine is greater than that of the complete launch vehicle, but is nonetheless useful because it determines the maximum acceleration that ''any'' vehicle using that engine could theoretically achieve with minimum propellant and structure attached.

For a takeoff from the surface of the [[earth]] using thrust and no [[aerodynamic lift]], the thrust-to-weight ratio for the whole vehicle must be greater than ''one''. In general, the thrust-to-weight ratio is numerically equal to the ''[[g-force]]'' that the vehicle can generate.<ref name="sutton"/> Take-off can occur when the vehicle's ''g-force'' exceeds local gravity (expressed as a multiple of ''g''{{sub|0}}).

The thrust-to-weight ratio of rockets typically greatly exceeds that of [[airbreathing jet engine]]s because the comparatively far greater density of rocket fuel eliminates the need for much engineering materials to pressurize it.

Many factors affect thrust-to-weight ratio. The instantaneous value typically varies over the duration of flight with the variations in thrust due to speed and altitude, together with changes in weight due to the amount of remaining propellant, and payload mass. Factors with the greatest effect include freestream air [[temperature]], [[pressure]], [[density]], and composition. Depending on the engine or vehicle under consideration, the actual performance will often be affected by [[buoyancy]] and local [[Field strength#Gravitational field strength|gravitational field strength]].

==Examples==

===Aircraft===

{| class="wikitable sortable"
|-
! Vehicle
! thrust-weight ratio
! Notes
|-
| [[B-2 Spirit|Northrop Grumman B-2 Spirit]]
| 0.205<ref>[[Northrop Grumman B-2 Spirit]]</ref>
| Max take-off weight, full power
|-
| [[Airbus A340|Airbus A340-300 Enhanced]]
| 0.2229
| Max take-off weight, full power
|-
| [[Airbus A380]]
| 0.227
| Max take-off weight, full power
|-
| [[Boeing 747-8]]
| 0.269
| Max take-off weight, full power
|-
| [[Boeing 777|Boeing 777-200ER]]
| 0.285
|  Max take-off weight, full power
|-
| [[Boeing 737 MAX|Boeing 737 MAX 8]]
| 0.311
| Max take-off weight, full power
|-
| [[Airbus A320neo family|Airbus A320neo]]
| 0.310
| Max take-off weight, full power
|-
| [[Boeing 757-200]]
| 0.341
| Max take-off weight, full power (w/Rolls-Royce RB211)
|-
| [[Tupolev Tu-154|Tupolev 154B]]
| 0.360
| Max take-off weight, full power (w/Kuznetsov NK-8-2)
|-
| [[Tupolev Tu-160]]
| 0.363 {{citation needed|date=July 2022}}
| Max take-off weight, full [[afterburners]]
|-
| [[Concorde]]
| 0.372
| Max take-off weight, full afterburners
|-
| [[Rockwell B-1 Lancer|Rockwell International B-1 Lancer]]
| 0.38
| Max take-off weight, full afterburners
|-
| [[HESA Kowsar]]
| 0.61
| With full fuel, afterburners.
|-
| [[BAE Systems Hawk|BAE Hawk]]
| 0.65<ref>[[BAE Systems Hawk]]</ref>
| 
|-
| [[English Electric Lightning|Lightning F.6]]
| 0.702
| Max take-off weight, full afterburners
|-
| [[Lockheed Martin F-35 Lightning II|Lockheed Martin F-35 A]]
| 0.87 {{citation needed|reason=No source|date=October 2023}}
| With full fuel (1.07 with 50% fuel, 1.19 with 25% fuel)
|-
| [[HAL Tejas|HAL Tejas Mk 1]]
| 1.07
| With full fuel
|-
| [[CAC/PAC JF-17 Thunder]]
| 1.07
| With full fuel
|-
| [[Dassault Rafale]]
| 0.988<ref>{{cite web|url=http://www.aviationsmilitaires.net/display/variant/1|title=AviationsMilitaires.net — Dassault Rafale C|website=www.aviationsmilitaires.net|access-date=30 April 2018|url-status=live|archive-url=https://web.archive.org/web/20140225213942/http://www.aviationsmilitaires.net/display/variant/1|archive-date=25 February 2014}}</ref>
| Version M, 100% fuel, 2 EM A2A missile, 2 IR A2A missiles
|-
| [[Su-30MKM|Sukhoi Su-30MKM]]
| 1.00<ref name="Wikipedia">[[Sukhoi Su-30MKM#Specifications .28Su-30MKM.29]]</ref>
| Loaded weight with 56% internal fuel
|-
| [[McDonnell Douglas F-15 Eagle|McDonnell Douglas F-15]]
| 1.04<ref>{{cite web
  | publisher = About.com:Inventors
  | title = F-15 Eagle Aircraft
  | url = http://inventors.about.com/library/inventors/blF_15_Eagle.htm
  | archive-url = https://archive.today/20120709021041/http://inventors.about.com/library/inventors/blF_15_Eagle.htm
  | url-status = dead
  | archive-date = July 9, 2012
  | access-date = 2009-03-03
  }}</ref>
| Nominally loaded
|-
| [[Mikoyan MiG-29]]
| 1.09<ref name=militaire>{{cite web|url=http://www.globalsecurity.org/military/world/russia/mig-29-specs.htm|title=MiG-29 FULCRUM|first=John|last=Pike|website=www.globalsecurity.org|access-date=30 April 2018|url-status=live|archive-url=https://web.archive.org/web/20170819232555/http://www.globalsecurity.org/military/world/russia/mig-29-specs.htm|archive-date=19 August 2017}}</ref>
| Full internal fuel, 4 AAMs
|-
| [[Lockheed Martin F-22 Raptor|Lockheed Martin F-22]]
| {{sort| 1.09 | >1.09 (1.26 with loaded weight and 50% fuel)<ref name=militaire2>{{cite web|url=http://www.aviationsmilitaires.net/display/aircraft/87/f_a-22|title=AviationsMilitaires.net — Lockheed-Martin F-22 Raptor|website=www.aviationsmilitaires.net|access-date=30 April 2018|url-status=live|archive-url=https://web.archive.org/web/20140225213945/http://www.aviationsmilitaires.net/display/aircraft/87/f_a-22|archive-date=25 February 2014}}</ref>}}
| 
|-
| [[General Dynamics F-16 Fighting Falcon|General Dynamics F-16]]
| 1.096{{Citation needed|date=July 2008}} (1.24 with loaded weight & 50% fuel)
|
|-
| [[Hawker Siddeley Harrier]]
| 1.1{{Citation needed|date=July 2008}}
| [[VTOL]]
|-
| [[Eurofighter Typhoon]]
| 1.15<ref>{{cite web|url=http://eurofighter.airpower.at/vergleich.htm|title=Eurofighter Typhoon|website=eurofighter.airpower.at|access-date=30 April 2018|url-status=live|archive-url=https://web.archive.org/web/20161109033535/http://eurofighter.airpower.at/vergleich.htm|archive-date=9 November 2016}}</ref>
| Interceptor configuration
|-
|[[Sukhoi Su-35]]
|1.30
|
|-
| [[Space Shuttle]]
| 1.3<ref>{{Cite web |last=Lee |first=Kwan-Jie |last2=Minet |first2=Lucas |last3=Lee |first3=Angela |title=lwtech 2021 velocity and acceleration profiles of space shuttles |url=https://www.lwtech.edu/academics/undergraduate-research-at-lwtech/annual-applied-research-symposium/symposium-e-portfolio/docs/lwtech-2021-velocity-and-acceleration-profiles-of-space-shuttles.pdf |url-status=dead |archive-url=https://web.archive.org/web/20220811212954/https://www.lwtech.edu/academics/undergraduate-research-at-lwtech/annual-applied-research-symposium/symposium-e-portfolio/docs/lwtech-2021-velocity-and-acceleration-profiles-of-space-shuttles.pdf |archive-date=August 11, 2022 |access-date=February 14, 2025 |website=lwtech}}</ref>
| Take-off
|-
| [[Simorgh (rocket)]]
| 1.83
|
|-
| [[Space Shuttle]]
| 3
| Peak
|}

===Jet and rocket engines===
{{sticky header}}
{| class="wikitable sortable sticky-header-multi"
|-
! rowspan=2 | Engine
! rowspan="2" | Mass
! colspan=2 | Thrust, vacuum
! rowspan=2 | Thrust-to-<br/>weight ratio
|-
! (kN)
! (lbf)
|-
|[[Jonker JS-1 Revelation|MD-TJ42]] powered sailplane jet engine<ref>{{Cite web |title=EASA.E.099 - MD-TJ series engines {{!}} EASA |url=https://www.easa.europa.eu/en/document-library/type-certificates/engine-cs-e/easae099-md-tj-series-engines |access-date=2024-11-08 |website=www.easa.europa.eu |language=en}}</ref>
|align=right|3.85kg (8.48 lb)
|align=right|0.35
|align=right|78.7
|align=right|9.09
|-
| [[RD-0410]] nuclear rocket engine<ref name="astronautix1">{{cite web|url=http://www.astronautix.com/engines/rd0410.htm|title=RD-0410 |last=Wade|first=Mark|publisher=[[Encyclopedia Astronautica]]|access-date=2009-09-25}}</ref><ref name="KBKhA-RD0410">{{cite web |title= |script-title=ru: РД0410. Ядерный ракетный двигатель. Перспективные космические аппараты |trans-title=RD0410. Nuclear Rocket Engine. Advanced launch vehicles |url=http://www.kbkha.ru/?p=8&cat=11&prod=66 |url-status=dead |archive-url=https://web.archive.org/web/20101130084749/http://www.kbkha.ru/?p=8&cat=11&prod=66 |archive-date=30 November 2010 |publisher=KBKhA - [[Chemical Automatics Design Bureau]] |language=ru}}</ref>

|align=right| {{Convert|2000|kg|abbr=on}}
|align=right| 35.2
|align=right| {{convert|35.2|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:35.2/(2000*0.00980665)round 1}}}}
|-
| [[Pratt & Whitney J58]] jet engine<br>([[Lockheed SR-71 Blackbird]])<ref>{{cite web| url=http://www.marchfield.org/sr71a.htm| archive-url=https://web.archive.org/web/20120729002902/http://www.marchfield.org/sr71a.htm| title=Aircraft: Lockheed SR-71A Blackbird| archive-date=2012-07-29| access-date=2010-04-16| url-status=dead}}</ref><ref>{{cite web| url=http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=880 |archive-url=https://web.archive.org/web/20150404113157/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=880| title=Factsheets : Pratt & Whitney J58 Turbojet| publisher=National Museum of the United States Air Force| access-date=2010-04-15| archive-date=2015-04-04| url-status=dead}}</ref>
|align=right| {{Convert|2722|kg|abbr=on}}
|align=right| 150
|align=right| {{convert|150|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:150/(2722*0.00980665)round 1}}}}
|-
| [[Rolls-Royce/Snecma Olympus 593]]<br />[[turbojet]] with reheat <br>([[Concorde]])<ref>{{cite web |title=Rolls-Royce SNECMA Olympus - Jane's Transport News |url=http://www.janes.com/transport/news/jae/jae000725_1_n.shtml |archive-url=https://web.archive.org/web/20100806140324/http://www.janes.com/transport/news/jae/jae000725_1_n.shtml| archive-date=2010-08-06 |url-status=dead |quote=With afterburner, reverser and nozzle ... 3,175 kg ... Afterburner ... 169.2 kN |access-date=2009-09-25}}</ref>
|align=right| {{Convert|3,175|kg|abbr=on}}
|align=right| 169.2
|align=right| {{convert|169.2|kN|lbf|disp=output number only}}
|align=right |{{formatnum:{{#expr:169.2/(3175*0.00980665)round 1}}}}
|-
| [[Pratt & Whitney F119]]<ref>[http://www.rand.org/pubs/monograph_reports/2005/MR1596.pdf Military Jet Engine Acquisition], RAND, 2002.</ref>
|align=right| {{Cvt|1800|kg}}
|align=right| {{convert|20500|lbf|kN|disp=output number only}}
|align=right| {{formatnum:20500}}
|align=right| {{formatnum:7.95}}
|-
| PBS TJ40-G1NS jet engine<ref>{{cite web |title=PBS TJ40-G1NS |url=https://www.pbs.cz/en/Aerospace/Aircraft-Engines/Jet-Engines-PBS-TJ40-G1NS |publisher=PBS Velká Bíteš |access-date=20 July 2024}}</ref>
|align=right| {{Cvt|3.6|kg}}
|align=right| {{formatnum:0.425}}
|align=right| {{convert|425|N|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:425/(3.6*9.80665)round 2}}}}
|-
| [[RD-0750]] rocket engine<br> three-propellant mode<ref name="KBKhA-RD0750">{{cite web |script-title = ru:"Конструкторское бюро химавтоматики" - Научно-исследовательский комплекс / РД0750. |trans-title=«Konstruktorskoe Buro Khimavtomatiky» - Scientific-Research Complex / RD0750. |publisher=KBKhA - [[Chemical Automatics Design Bureau]] |url=http://www.kbkha.ru/?p=8&cat=11&prod=57 |archive-url = https://web.archive.org/web/20110726074426/http://www.kbkha.ru/?p=8&cat=11&prod=57 |archive-date = 26 July 2011 |url-status = dead}}</ref>

|align=right| {{Convert|4,621|kg|abbr=on}}
|align=right| {{formatnum:1413}}
|align=right| {{convert|1413|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:1413/(4621*0.00980665)round 1}}}}
|-
| [[RD-0146]] rocket engine<ref name="astronautix2">{{cite web|url=http://www.astronautix.com/engines/rd0146.htm|title=RD-0146 |last=Wade|first=Mark|publisher=[[Encyclopedia Astronautica]]|access-date=2009-09-25}}</ref>

|align=right| {{Convert|260|kg|abbr=on}}
|align=right| {{formatnum:98}}
|align=right| {{convert|98|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:98/(260*0.00980665)round 1}}}}
|-
| [[Aerojet Rocketdyne|Rocketdyne]] [[RS-25]] rocket engine<br>(Space Shuttle Main Engine)<ref>[http://www.astronautix.com/engines/ssme.htm SSME]</ref>

|align=right| {{Convert|3177|kg|abbr=on}}
|align=right| {{formatnum:2278}}
|align=right| {{convert|2278|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:2278/(3177*0.00980665)round 1}}}}
|-
|[[RD-180]] rocket engine<ref>{{cite web |title=RD-180 |url=http://www.astronautix.com/engines/rd180.htm |access-date=2009-09-25}}</ref>
|align=right| {{convert|5393|kg|abbr=on}}
|align=right| {{formatnum:4152}}
|align=right| {{convert|4152|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:4152/(5383*0.00980665)round 1}}}}
|-
| [[RD-170]] rocket engine
|align=right| {{Convert|9750|kg|abbr=on}}
|align=right| {{formatnum:7887}}
|align=right| {{convert|7887|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:7887/(9750*0.00980665)round 1}}}}
|-
| [[F-1 (rocket engine)|F-1]]<br>([[Saturn V]] first stage)<ref>[http://www.astronautix.com/engines/f1.htm Encyclopedia Astronautica: F-1]</ref>
|align=right| {{Convert|8391|kg|abbr=on}}
|align=right| {{formatnum:7740.5}}
|align=right| {{convert|7740.5|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:7740.5/(8391*0.00980665)round 1}}}}
|-
| [[NK-33]] rocket engine<ref name="NK33">{{Cite encyclopedia |encyclopedia=Encyclopedia Astronautica |title= NK-33 |url=http://www.astronautix.com/n/nk-33.html |access-date=2022-08-24 |first= Mark |last=Wade}}</ref>
|align=right| {{Convert|1222|kg|abbr=on}}
|align=right| {{formatnum:1638}}
|align=right| {{convert|1638|kN|lbf|disp=output number only}}
|align=right| {{formatnum:{{#expr:1638/(1222*0.00980665)round 1}}}}
|-
| [[SpaceX Raptor]] 3 rocket engine<ref>{{Cite web |last=Sesnic |first=Trevor |date=2022-07-14 |title=Raptor 1 vs Raptor 2: What did SpaceX change? |url=https://everydayastronaut.com/spacex-raptor-engine-comparison/ |access-date=2022-11-07 |website=Everyday Astronaut |language=en-US}}</ref>
|align=right| {{Convert|1525|kg|abbr=on}}
|align=right| 2,746
|align=right| {{convert|2746|kN|lbf|disp=output number only}}
|align=right| 183.6
|-
| [[Merlin 1D]] rocket engine, <br>full-thrust version<ref name="Merlin 1D">{{cite web |last=Mueller |first=Thomas |title=Is SpaceX's Merlin 1D's thrust-to-weight ratio of 150+ believable? |work=Quora |url=https://www.quora.com/Is-SpaceXs-Merlin-1Ds-thrust-to-weight-ratio-of-150+-believable/answer/Thomas-Mueller-11 |access-date=July 9, 2015 |date=June 8, 2015 |quote=The Merlin 1D weighs 1030 pounds, including the hydraulic steering (TVC) actuators. It makes 162,500 pounds of thrust in vacuum. that is nearly 158 thrust/weight. The new full thrust variant weighs the same and makes about 185,500 lbs force in vacuum.}}</ref><ref>{{Cite web |title=SpaceX |url=http://www.spacex.com/ |access-date=2022-11-07 |website=SpaceX |language=en}}</ref>
|align=right| {{Cvt|467|kg}}
|align=right| 914
|align=right| 205,500
|align=right| 199.5
|}

=== Fighter aircraft ===

{| class="wikitable"
|+ Thrust-to-weight ratios, fuel weights, and weights of different fighter planes
|-
!Specifications
! [[McDonnell Douglas F-15E Strike Eagle|F-15K]]{{efn| Pratt & Whitney engines}}
! F-15C
! MiG-29K
! MiG-29B
! [[CAC/PAC JF-17 Thunder|JF-17]]
! [[Chengdu J-10|J-10]]
! F-35A
! F-35B
! F-35C
! F-22
! [[HAL Tejas|LCA Mk-1]]
|-
| Engines thrust, maximum (N)
| 259,420 (2)
| 208,622 (2)
| 176,514 (2)
| 162,805 (2)
| 84,400 (1)
| 122,580 (1)
| 177,484 (1)
| 177,484 (1)
| 177,484 (1)
| 311,376 (2)
| 84,516 (1)
|-
| Aircraft mass, empty (kg)
| 17,010
| 14,379
| 12,723
| 10,900
| 7,965
| 09,250
| 13,290
| 14,515
| 15,785
| 19,673
|  6,560
|-
| Aircraft mass, full fuel (kg)
| 23,143
| 20,671
| 17,963
| 14,405
| 11,365
| 13,044
| 21,672
| 20,867
| 24,403
| 27,836
|  9,500
|-
| Aircraft mass, max. take-off load (kg)
| 36,741
| 30,845
| 22,400
| 18,500
| 13,500
| 19,277
| 31,752
| 27,216
| 31,752
| 37,869
| 13,500
|-
| Total fuel mass (kg)
| 06,133
| 06,292
| 05,240
| 03,505
| 02,300
| 03,794
| 08,382
| 06,352
| 08,618
| 08,163
| 02,458
|-
| T/W ratio, full fuel
| 1.14
| 1.03
| 1.00
| 1.15
| 1.07
| 1.05
| 0.84
| 0.87
| 0.74
| 1.14
| 1.07
|-
| T/W ratio, max. take-off load
| 0.72
| 0.69
| 0.80
| 0.89
| 0.70
| 0.80
| 0.57
| 0.67
| 0.57
| 0.84
| 0.80
|}

* Table for Jet and rocket engines: jet thrust is at sea level
* Fuel density used in calculations: 0.803&nbsp;kg/l
* For the metric table, the ''T''/''W'' ratio is calculated by dividing the thrust by the product of the full fuel aircraft weight and the acceleration of gravity.
* J-10's engine rating is of AL-31FN.

==See also==
* [[Power-to-weight ratio]]
* [[Factor of safety]]

==Notes==
{{notelist}}
{{Reflist|30em}}

==References==
* John P. Fielding. ''Introduction to Aircraft Design'', Cambridge University Press, {{ISBN|978-0-521-65722-8}}
* Daniel P. Raymer (1989). ''Aircraft Design: A Conceptual Approach'', American Institute of Aeronautics and Astronautics, Inc., Washington, DC. {{ISBN|0-930403-51-7}}
* George P. Sutton & Oscar Biblarz. ''Rocket Propulsion Elements'', Wiley, {{ISBN|978-0-471-32642-7}}

==External links==
* [http://www.grc.nasa.gov/WWW/K-12/airplane/fwrat.html NASA webpage with overview and explanatory diagram of aircraft thrust to weight ratio]

{{DEFAULTSORT:Thrust-To-Weight Ratio}}
[[Category:Jet engines]]
[[Category:Rocket engines]]
[[Category:Engineering ratios]]