Rowing Watts to 500m Split Calculator
Convert Concept2 erg watts to a 500m split, or a split to watts, with the official formula (watts = 2.80 ÷ pace³). Also shows speed, race times at that pace, Paul’s Law predictions, calories per hour as the monitor shows them and for your weight, watts per kg, distance per stroke and a watts–split table.
How it works
Pace (s/m) = (2.80 ÷ watts)^(1/3) · 500m split = pace × 500 · Watts = 2.80 ÷ pace³ · Monitor kcal/h = watts × 4 × 0.8604 + 300 · Your kcal/h = monitor − 300 + 1.714 × weight (lb) · Paul’s Law: +5 s per 500 m each time the distance doubles
Concept2 rowing machines link power and pace with watts = 2.80 ÷ pace³, where pace is seconds per metre. Inverting it, pace is the cube root of 2.80 divided by watts, and multiplying by 500 gives the 500m split shown on the monitor. You can convert either way: enter watts to get the split, or a split to get watts. Because power rises with the cube of speed, halving your split takes eight times the power, which is why the last few seconds cost so much. The calculator also gives the 2,000 m time and the distance for a workout of any length at that pace. Calories are shown two ways: the figure the monitor displays, which assumes a 175 lb rower, and Concept2’s weight-corrected figure. You also get watts per kilogram, distance and work per stroke at your stroke rate, and the weight-adjusted 2k Concept2 uses to compare lighter and heavier rowers. A race table gives times at your pace and Paul’s Law predictions, which add about 5 seconds to the split each time the distance doubles.
Worked example
At 200 watts: pace = (2.80 ÷ 200)^(1/3) = 0.2410 s/m, so the 500m split is 0.2410 × 500 = 120.5 seconds, or 2:00.5 per 500m. That is 4.15 m/s, and a 2,000 m piece at that pace takes 8:02. The monitor shows 200 × 4 × 0.8604 + 300 ≈ 988 kcal per hour. Going the other way, a 1:45.0 split is 105 s ÷ 500 = 0.21 s/m, and 2.80 ÷ 0.21³ ≈ 302 W.
Sources: Concept2 — Pace and watts calculators · Concept2 — Calorie calculator · Concept2 — Weight adjustment calculator
Frequently asked questions
Why does a small split drop need so much more power?
Power rises with the cube of speed. Going from a 2:00 to a 1:50 split, about 9% faster, takes roughly 30% more watts. Sprinting the last 500 m costs power out of all proportion to the time saved.
Does this match my Concept2 monitor?
Yes. This is the formula Concept2 uses to display watts and pace, and it does not depend on the damper setting, so the split here matches the PM monitor for the same power.
Are the calories on the erg accurate?
The monitor assumes everyone weighs 175 lb (79.4 kg). Concept2’s correction is: monitor calories per hour − 300 + 1.714 × your weight in pounds. A lighter rower burns less than the screen shows at the same pace, and a heavier rower more. Enter your weight under More options to get the corrected figure.
What is Paul’s Law?
A rule of thumb named after Paul Smith, who proposed it: for a well-trained rower, the 500m split gets about 5 seconds slower each time the race distance doubles. If you can hold 1:50 for 2,000 m, expect about 1:55 for 4,000 m and 2:00 for 8,000 m. Use it as a rough guide.
What is a good watts-per-kilogram on the erg?
Over a 2,000 m piece, about 3 W/kg is a decent recreational level (a 7:30 2k for an 80 kg rower is about 3.1 W/kg). Club racers are often around 4–4.5 W/kg, and elite heavyweight men about 6 W/kg.
Related calculators
This calculator is for educational purposes. Double-check important results before acting on them.