Calculate power, torque, or rotational speed from any two values in watts, kW, HP, RPM, rad/s, Nm, or lb-ft, and find the missing one.

Watts To Torque Calculator

Enter any 2 values to calculate the missing variable

Watts To Torque Formula

The following formula is used to calculate torque from power (watts).

T = P / ω

Variables:

  • T is the torque (Nm)
  • P is the power (Watts)
  • ω is the rotational speed (rad/s)

To calculate the torque, divide the power by the rotational speed. This will give the torque in Newton meters (Nm). It’s important to note that the rotational speed must be in radians per second for this formula to work correctly.

Watts to Torque Conversion Table (Assumes 1000 RPM; ω = 104.72 rad/s)
Power (W) Torque (Nm) Torque (lb-ft)
500.4770.352
1000.9550.704
1501.4321.056
2001.9101.409
2502.3871.761
3002.8652.113
5004.7753.522
7507.1625.282
10009.5497.043
150014.32410.565
200019.09914.086
250023.87317.608
300028.64821.130
400038.19728.173
500047.74635.216
750071.62052.824
1000095.49370.432
15000143.239105.648
20000190.986140.864
25000238.732176.080
* Rounded to 3 decimals. Assumes constant speed of 1000 RPM (ω = 2π·RPM/60 ≈ 104.72 rad/s). Formula: T = P / ω. 1 Nm ≈ 0.737562 lb-ft (1 lb-ft ≈ 1.35582 Nm).

What is Watts To Torque?

Watts to Torque refers to the conversion of power (measured in watts) to torque (a measure of rotational or twisting force). This conversion is important in various fields such as engineering and physics, as it helps to understand and quantify the amount of work or energy required to produce a certain level of torque. The relationship between power, torque, and rotational speed is defined by the formula: Power = Torque x Rotational Speed. Therefore, to convert watts to torque, the rotational speed must be known or estimated.

How to Calculate Watts To Torque?

The following steps outline how to calculate the Watts To Torque using the formula T = P / ω.


  1. First, determine the power (P) in Watts.
  2. Next, determine the rotational speed (ω) in rad/s.
  3. Next, gather the formula from above = T = P / ω.
  4. Finally, calculate the torque (T) in Nm.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

power (P) in Watts = 500

rotational speed (ω) in rad/s = 100