Enter any three values (piston area, equivalent piston speed, mean effective pressure, or power) into the calculator to determine the missing value for steam engine (indicated) power.

Steam Engine Power Calculator

Power from Area, Speed, Pressure
Piston Speed
Cylinder Area

Enter any 3 values to calculate the missing variable

Steam Engine Power Formula

The following formula is used to calculate steam engine (indicated) power from mean effective pressure, piston area, and equivalent piston speed. 

P_{se} = \frac{P \cdot A \cdot S}{33{,}000}
  • Where Pse is the steam engine power (HP)
  • P is the mean effective pressure (psi)
  • A is the area of piston (in^2) 
  • S is the equivalent piston speed (ft/min) 

To calculate steam engine power (HP), multiply the mean effective pressure by the piston area and equivalent piston speed, then divide by 33,000.

How to Calculate Steam Engine Power?

The following two example problems outline how to calculate the Steam Engine Power.

Example Problem #1:

  1. First, determine the area of piston (in^2). In this example, the area of piston (in^2) is measured to be 16.
  2. Next, determine the equivalent piston speed (ft/min). For this problem, the equivalent piston speed (ft/min) is calculated to be 71.
  3. Next, determine the mean effective pressure (psi). For this example, assume a mean effective pressure of 60 psi.
  4. Finally, calculate the Steam Engine Power using the formula above: 

Pse = (P*A*S) /33,000

Inserting the values from above and solving the equation with the input values gives: 

Pse = 60*16*71 /33,000 = 2.065 (HP)


Example Problem #2: 

Using the same process as example problem 1, we first define the variables outlined by the formula. In this case, the values are:

area of piston (in^2) = 3

equivalent piston speed (ft/min) = 1000

mean effective pressure (psi) = 60

Entering these values into the formula or calculator above gives us: 

Pse = 60*3*1000 /33,000 = 5.455 (HP)