Erg Pace + Watts Calculator
For Concept2 RowErg, SkiErg, and BikeErg. Plug in any two of distance, time, or split — get the third plus the watts and calorie estimate. Same math Concept2's PM5 monitor uses internally.
Reading the outputs
- Split / 500 m — your "pace" on the erg. The standard reference unit. 2:00/500m = 4:00 for 1k = 8:00 for 2k.
- Watts — instantaneous power output. The same watts on RowErg, SkiErg, and BikeErg represent the same energy.
- Pace / 1000 m — for sessions where 500m feels too short to mentally track.
- Calories / hr — Concept2's formula
(4 × watts) + 350. Indicative only; varies with bodyweight.
Common reference workouts
| Workout | Distance | Notes |
|---|---|---|
| 500m | 500 | Sprint test — VO2max indicator. |
| 2k | 2000 | Standard test piece. The "marathon time" of erg. |
| 5k | 5000 | Aerobic threshold benchmark. |
| 6k | 6000 | Common collegiate test. |
| 10k | 10000 | Long aerobic. ~35 min for elite, 45–55 for recreational. |
| 30 min / 60 min | — | Time-based test. Distance achieved is the score. |
The math
Concept2 publishes a single curve mapping power to pace:
watts = 2.80 / (pace_in_seconds_per_meter)3
Equivalently, seconds_per_meter = (2.80 / watts)1/3.
Multiply by 500 to get split. The cube relationship is why dropping
your split a few seconds takes a lot more watts than you'd expect —
going from 2:00/500m to 1:55/500m is roughly a 13% increase in power,
not a small change.
Cross-machine comparisons
- 250 W on RowErg ≈ 250 W on SkiErg ≈ 250 W on BikeErg. Same energy, different muscles.
- Splits differ slightly in feel because of the technique. SkiErg pulls feel more cardiovascular at the same wattage; BikeErg loads the legs more.
- The PM5 rolls all three the same way. If you can hit 1:50/500m on the rower, you can probably hit 1:50/500m on the ski erg with practice — same wattage demand.
Sharing a scenario
The URL hash carries the inputs. Send a coach the URL of "5k @ 1:55/500m" and they see exactly what you're targeting.
FAQ
Where does the watts ↔ split formula come from?
It's Concept2's published curve: watts = 2.80 / (pace_seconds_per_meter)3. The same formula applies to RowErg, SkiErg, and BikeErg — all three machines use Concept2's flywheel and report power the same way. The split (time per 500 m) is just 500 × seconds_per_meter.
Does it really work for all three machines?
Yes — Concept2's design intent is that 250 W on a RowErg, 250 W on a SkiErg, and 250 W on a BikeErg all represent the same energy output, displayed the same way. The actual stroke / push / cadence differs, but the watts and split numbers are directly comparable. Cross-training between machines is the whole point.
How accurate is the calorie estimate?
Concept2's formula is cals/hr ≈ (4 × watts) + 350. It's a rough estimator — calorie burn varies with bodyweight (heavier athletes burn more for the same watts), but the +350 baseline is a pragmatic average. Your monitor's number is computed the same way.
Why does my time on the machine differ slightly from this?
The PM5 monitor rounds to 0.1s and reports actual measured pace, which fluctuates stroke to stroke. This calculator gives you the math for a perfectly held pace. Real-world variation of ±1–2 seconds over a 2k is normal.
Is anything I enter sent to a server?
No. All math is in your browser. The URL hash carries the scenario but only your own browser sees it.