Rowing Calculator
Rowing machine split per 500 m to watts and back with Concept2's formula, calories per hour, and the finish time for any distance at a split.
Result…
How it's calculated
Pace (s/m) = split ÷ 500 Watts = 2.80 ÷ pace³; pace = ∛(2.80 ÷ watts) Finish time = split × distance ÷ 500 Monitor Calories/hour = watts × 4 × 0.8604 + 300 For your weight: Calories/hour − 300 + 1.714 × weight in lb
Concept2 publishes the formulas its performance monitors use. Power is 2.80 divided by the cube of the pace in seconds per metre, so a 2:05 split (125 s per 500 m, a pace of 0.25 s/m) is 2.80 ÷ 0.25³ = 179.2 W. The monitor's Calories per hour assume a 175 lb (79.5 kg) person; Concept2's weight adjustment removes 300 and adds 1.714 Calories per hour for each pound of body weight.
Your numbers, step by step
About the Rowing calculator
This rowing calculator converts a rowing machine split per 500 m into watts and back, using the formula Concept2 publishes for its indoor rowers: watts = 2.80 ÷ pace³, with pace in seconds per metre. You can also start from a distance and the time it took to get your average split. For any split it gives the finish time for a distance you choose, such as a 2000 m test or a 5 km piece, plus your average speed in km/h and mph. Calories per hour follow the monitor's own formula, and you can adjust them for your body weight the way Concept2's calorie calculator does, then see the total for the piece. It is useful for planning a target split, comparing a watts-based workout with a split-based one, or checking a result. Each step of the working is shown.
How to use it
- Choose what “I know my”: split, watts, or distance and time.
- Enter the “Split per 500 m” as minutes:seconds.tenths, the “Average power” in watts, or the “Time taken”.
- Enter the “Distance” and its unit for the finish time.
- Choose whether to “Adjust calories for my weight” and, if so, enter your “Body weight”.
- Read the watts or split, the finish time, calories per hour and calories for the distance.
Worked example
A 2:00.0 split is 120 s per 500 m, a pace of 0.24 s/m, so the power is 2.80 ÷ 0.24³ = 202.5 W. A 2000 m piece at that split takes 120 × 2000 ÷ 500 = 480 s, which is 8:00.0. The monitor shows 202.5 × 3.4416 + 300 = 997 Calories per hour; adjusted for a 70 kg (154.3 lb) rower that becomes 997 − 300 + 1.714 × 154.3 = 962 Calories per hour, or about 128 for the 8 minutes.
Updated
Questions people ask
How do I convert a rowing split to watts?
Divide the split in seconds by 500 to get the pace in seconds per metre, cube it, and divide 2.80 by the result. Concept2's own example: 2:05 is 125 s, a pace of 0.25, and 2.80 ÷ 0.25³ = 179.2 W.
What split do I need for a target 2000 m time?
Divide the target time by 4, since 2000 m is four 500 m lengths. A 7:20 finish needs a 1:50 split; choose distance and time to see it with the watts.
Why does a slightly faster split need so many more watts?
Power goes with the cube of speed, so going from 2:00 to 1:50 takes about 30% more power, not 9%. A common mistake is pacing a piece by feel at the start and running out of power later.
How does the rower count calories?
Concept2 gives the monitor's formula as watts × 4 × 0.8604 + 300 Calories per hour, set for a 175 lb (79.5 kg) person. Its calorie calculator adjusts this by removing 300 and adding 1.714 for each pound of body weight.
Do the numbers match other rowing machines?
They follow Concept2's published formulas (watts calculator), so other brands may show different watts or calories for the same effort. For running paces instead, use the pace calculator.
How accurate is the calorie estimate?
It is an estimate from power output and weight, not a measurement of your own metabolism, and it is information, not medical advice. If you are training around a health condition or a weight goal, talk to a doctor or qualified coach.