Mean Piston Speed Calculator
Average piston speed at a given engine speed, and the rpm that reaches 20 m/s.
Results
Mean piston speed
17.200
m/s
Speed
3386
ft/min
Rotational speed
6977
rpm
What this tool does
Mean piston speed is the honest measure of how hard an engine is working: road engines rarely pass 20 m/s, while racing engines reach 25 and beyond with materials to match. A long-stroke engine hits its limit at far lower rpm than a short-stroke one.
Formula
v = 2 × stroke × n ÷ 60
Variables
| Symbol | Meaning | Unit |
|---|---|---|
s | Stroke | mm |
n | Rotational speed | rpm |
V | Mean piston speed | m/s |
VF | Speed | ft/min |
N | Rotational speed | rpm |
Worked example
- Stroke86 mm
- Rotational speed6000 rpm
- Mean piston speed17.200 m/s
- Speed3386 ft/min
- Rotational speed6977 rpm
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.