Rowing 2K Time Predictor
Predict your 2000m rowing time from a 500m sprint or 5000m piece.
Uses the Paul's Law extrapolation formula used by rowing coaches worldwide.
Paul’s Law — the most-used formula in rowing
Paul Smith published the rowing equivalent of Riegel’s running prediction in the early 1990s. The relationship between time and distance for trained rowers follows a power law:
time_2 ÷ time_1 = (distance_2 ÷ distance_1) ^ 1.06
The 1.06 exponent is the magic number. It says doubling the distance roughly doubles the time, but with a slight penalty (about 4%) because race pace falls as duration rises. Trained rowers fit this curve remarkably well — within ±2 seconds across the 500m to 5000m range — which is why coaches still trust it 30+ years on.
What the predictions actually look like
For a 1:34.5 over 500m, Paul’s Law predicts a 2K of about 6:34.
| Test piece | Equivalent 2K (if test = 7:30) | Equivalent 2K (if test = 6:30) |
|---|---|---|
| 500m at 1:48 | 7:30 | n/a |
| 1K at 3:38 | 7:30 | 6:30 (test 3:09) |
| 2K (the race) | 7:30 | 6:30 |
| 5K at 19:55 | 7:30 | 6:30 (test 17:16) |
| 6K at 24:00 | 7:30 | 6:30 |
So a 19:55 5K at the same fitness level as the 2K. If your 5K is faster than the prediction says, your 2K is undertrained on the top end. If it is slower, you have a fitness gap on the long-aerobic side.
Where the formula breaks
Paul’s Law assumes the rower is trained and pacing well. It overestimates 2K from a 500m if the sprint was a redline all-out PR — short pieces include alactic and creatine-phosphate energy that won’t carry to 2000m. It underestimates 2K from a long aerobic piece if pacing was conservative.
A more robust prediction uses two tests at different distances, and refits the exponent. Heavy rowers with strong anaerobic capacity sometimes fit closer to 1.08; lightweights with pure aerobic ability often fit 1.04 to 1.05.
What to do with the number
Predict your 2K, then train the gap. If the predictor says 6:45 and you can only hold 7:00 in a race, the gap is mental, pacing, or race-day taper, not fitness. If the predictor says 6:45 and your last 2K was 6:30, you have improved between tests — re-test soon to update the baseline.
The Concept2 logbook keeps a “best of all time” by distance which makes for a built-in Paul’s Law audit.