Stroke Efficiency Calculator
Measure how efficiently you convert each stroke into boat speed. Calculate distance per stroke, watts per stroke, and SPI.
:/500m
spm
Reference table
| Split | Rate | m/stroke | SPI |
|---|---|---|---|
| 02:00.0 | 20 spm | 12.5 | 52.08 |
| 02:00.0 | 24 spm | 10.4 | 43.40 |
| 02:00.0 | 28 spm | 8.9 | 37.20 |
| 01:45.0 | 24 spm | 11.9 | 56.69 |
| 01:45.0 | 28 spm | 10.2 | 48.59 |
| 01:45.0 | 32 spm | 8.9 | 42.52 |
What is SPI?
Stroke Performance Index (SPI) = distance per stroke × speed. It measures how effectively you translate each stroke into forward movement. A higher SPI means more efficient rowing — you're getting more speed per stroke.
Improving SPI usually comes from better catch timing, a longer drive, and smoother recovery — not from pulling harder.
Check your watts or training zones to pair efficiency work with the right intensity.
Track stroke efficiency in every workout
ErgManiac logs stroke rate and calculates SPI for every piece you row.
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