Thrust to Weight Ratio Calculator
This thrust to weight ratio calculator assists engineers in estimating the thrust to weight ratio of a vehicle. The thrust to weight ratio is crucial data when it comes to designing an aircraft, be it the smaller remotecontrolled (RC) drone or a fullfledged passenger jet. For instance, the thrust to weight ratio parameter will tell us about the maneuverability of an aircraft. Read on to understand how to calculate thrust to weight ratio of different aircraft.
Thrust to weight ratio
The thrust to weight ratio is defined as the ratio of the thrust available to the mass of the aircraft. It is a dimensionless quantity. In order to obtain the thrust to weight ratio, both values should be in appropriate units. For instance, if the thrust is in Newtons (N), and the weight is in kilograms (kg), the weight must be converted to mass to obtain the right answer. However, if the thrust is in poundsforce (lbf) and weight is in pounds (lb), the formula will give the correct answer. Mathematically, the ratio can be given by the equation:
The thrust to weight ratio can have multiple variations because of the different types of thrusts, and weights. For instance:
 Thrust — Could either be available value during normal engine conditions, maximum available value or in the afterburner conditions, where the thrust available is maximum.
 Weight — There are different types of aircraft weights such as gross weight, the maximum takeoff weight, weight at different fuel levels, say 50% or 100%, and empty weight.
The thrust to weight ratio can alternatively be defined as the inverse of the lift to drag ratio in cruise flight conditions. Mathematically, this is given as:
💡 Read more about the lift coefficient and the drag force at the lift coefficient calculator and drag equation calculator ✈
How to calculate thrust to weight ratio?
To calculate thrust to weight ratio:
 Enter the appropriate thrust value.
 Insert the weight of the aircraft.
 The calculator will return the thrust to weight ratio.
Note: You can use the advanced
mode of this calculator to directly pick the names of the aircraft or engines to find out their thrust to weight ratio parameter.
Example: Using the thrust to weight ratio calculator
There are two modes of this calculator — single mode or compare mode, if you want to calculate the thrust to weight ratio of an aircraft, you can pick single mode. If you wish to compare the thrust to weight parameter of two different aircraft, you can pick the compare mode.
Using the single mode:
Estimate the thrust to weight ratio of an aircraft weighing 10,000 kg and having 2 engines capable of producing a thrust of 40 kN each.

First of all, since the aircraft has two engines, we find the total thrust available, such that:
Thrust available = 2 * 40 = 80 kN

Enter the thrust available in the calculator as
80 kN
. 
Enter the weight of the aircraft as
10000 kg
. 
The thrust to weight ratio calculator will now return the value of thrust to weight ratio as
0.82
.
Using the compare mode:
This mode is used to compare two different configurations. Say, for example, you want to compare the thrust to weight ratio of an F16 Block 52 and HAL Tejas aircraft.
 Set the mode to
compare
andadvanced
to see the list of different aircraft and engines.  Select
F16 Block 52
from the list as Aircraft 1.  Select
HAL LCA Tejas Mk1
from the list as Aircraft 2.  The calculator will now calculate the thrust to weight ratio and compare them to tell you which configuration has a higher thrust to weight ratio.
Similarly, if you have your own data, you can calculate the thrust to weight ratio of commercial aircraft or drones too.
🙋 With the drone motor calculator, you can easily determine the thrust required for your drone to fly!
FAQ
What is the thrust to weight ratio?
Thrust to weight ratio is defined as the ratio of thrust available or maximum thrust to the weight of the aircraft. The weight could either be gross weight, the maximum takeoff weight, or at different fuel levels.
What is the thrust to weight ratio of an F16?
The F 16's thrust to weight ratio, considering its gross weight and thrust produced by the engines with afterburner is equal to 29,560 lbf / 26,500 lb, i.e., 1.11. The result may vary if you consider different types of weight or thrust.
What is the thrust to weight ratio of HAL Tejas?
The thrust to weight ratio of HAL Tejas Mk1, considering its gross weight and thrust produced by the engines with afterburner is equal to 20,200 lbf / 26,500 lb, i.e., 0.94. The result may vary if you consider different types of weight or thrust.
What is the thrust to weight ratio of JF17 Thunder?
The thrust to weight ratio of JF17 block 2, considering its weight at 50% fuel and thrust produced by the engines with afterburner is equal to 19,000 lbf / 20,000 lb, i.e., 0.95. The result may vary if you consider different types of weight or thrust.