Created By : Abhinandan Kumar

Reviewed By : Phani Ponnapalli

Last Updated : May 17, 2023

The BMEP calculator aids in determining an engine's BMEP (Brake Mean Effective Pressure), which is a useful metric for comparing the performance of similar engines. We'll learn what BMEP is, how to calculate an engine's BMEP, and more about the BMEP formula that has been used to determine this value. The Brake Mean Effective Pressure value gives you an idea of how efficient your engine is, so knowing what BMEP is - it's crucial.

Engine type
Engine displacement (Volume)
Torque (F)
Brake mean effective pressure

What is BMEP?

Brake Mean Effective Pressure is abbreviated to BMEP. The average pressure is applied across the pistons to generate the required torque is measured using our BMEP calculator. It is a measure of an engine's efficiency in using its size (displacement) to generate the required torque and is thus very useful in comparing engine performance.

It's also worth noting that the amount of air-fuel handled by the carburetor affects engine efficiency, and the carburetor CFM metric measures that volume.

BMEP Formula

The following is the formula for calculating BMEP:

BMEP = 2π * n * T / D


  • n - Number of revolutions per power stroke
  • T - Torque
  • D - Displacement (volume) of the engine
  • It should be noted that n has a standard value -
  • For a two-stroke engine n = 1
  • For a four-stroke engine n = 2.

How do we calculate an engine's BMEP?

Assume we have a four-stroke engine with a displacement of 2000 cc and a torque rating of 160 Nm. This is how we calculate the engine's BMEP -

  • Step 1: Set the engine type to 4-stroke in the BMEP calculator. n is automatically set to 2 once this option is selected.
  • Step 2: The torque value should be set to 160 Nm.
  • Step 3: Change the displacement to 2000 cc.
  • Step 4: The result of the BMEP calculator is 1,005.3 kPa.

Likewise, we can convert BMEP to torque using the same formula and rearrange it to solve for torque if we know the BMEP value. Converting BMEP to torque is especially helpful because torque is a key metric that represents the engine's load capacity.

You can also calculate the horsepower of different engines if you're interested to know how horsepower can help you compare engine efficiencies. You might also be interested in learning more about the various influences on piston speed and force.

How can BMEP be increased?

The most efficient way to increase BMEP is to increase the number of cylinders, which improves the engine's efficiency and, in turn, increases the BMEP value.

Find similar concepts of physics all under one roof explained clearly with step by step process on

FAQs on BMEP (Brake Mean Effective Pressure)

1. What is BMEP (brake mean effective pressure)?

The average pressure trying to force the pistons inside your engine down to produce the measured torque output is known as brake mean effective pressure (BMEP).

2. What is the formula for calculating braking effective pressure?

BMEP = (Torque x 75.4) / (Displacement x PPR)

3. From an indicator diagram, how do you calculate mean effective pressure?

The area is then divided by the diagram's length to obtain the mean height. The indicated mean effective pressure for the cylinder is calculated by multiplying this mean height by the spring scale of the indicator mechanism.

4. What is the method for calculating mean effective pressure?

The initial engine design calculations use mean effective pressure, and the engine designer can calculate the necessary engine volumetric capacity using engine torque and MEP as inputs.

5. What are the benefits of the BMEP?

The BMEP value has an interesting side effect: the higher the BMEP, the lower the fuel consumption and, as a result, the more efficient the engine!