HomeCalculatorsBrake Mean Effective Pressure (BMEP)

Brake Mean Effective Pressure (BMEP)

Single useful indicator of engine output intensity. BMEP = Pb·60·k / (V·N), where k=1 for 2-stroke, k=2 for 4-stroke.

Engine
BMEP
85.71bar
Formula, assumptions, and limits

Typical modern two-stroke BMEP 18–22 bar at MCR. Four-stroke medium-speed ~22–26 bar. BMEP is the most useful measure of a design's output intensity because it normalises for cylinder size and rpm.

Symbol legend

SymbolMeaningUnitSource
Brake powerkWNOx technical file
Total swept volumeL (= dm³)engine spec
Engine rpmrpmtachometer
1 for 2-stroke, 2 for 4-stroke - engine type
Brake mean effective pressurebarresult