Remonta

Free tool

Rowing split /500 m and watts calculator

Convert your erg split to watts and watts to a split, get the time for a distance or the split for a time, and watts per kilo if you enter your weight. Same formula as the PM5 monitor.

m:ss.t, for example 2:00.0
m:ss.t or h:mm:ss
Result Enter a split, some watts, or a distance and its time: the rest fills itself in.

The formula

How a split turns into watts.

The split is the time it takes to row 500 m. Divided by 500 it gives the pace in seconds per metre, and Concept2, maker of the indoor rower and the PM5 monitor, publishes the relationship between that pace and power:

watts = 2.80 / (split ÷ 500)³

A 2:00.0 split is 120 s ÷ 500 = 0.24 s/m, and 2.80 ÷ 0.24³ = 202.5 W, which the app rounds to 203 W. From watts to split it's the same sum backwards: split = 500 × ∛(2.80 ÷ watts). The time for a distance is the split times the metres over 500, and W/kg is watts over your weight.

Because power goes with the cube of pace, every second off your split costs more watts than the last: 2:00 to 1:55 is about 27 W; 1:35 to 1:30, over 70.

Splits /500 m from 1:30 to 2:30 with their watts and the 2000 m time at that pace.
Split /500 mWatts2000 m
1:30.0480 W6:00.0
1:35.0408 W6:20.0
1:40.0350 W6:40.0
1:45.0302 W7:00.0
1:50.0263 W7:20.0
1:55.0230 W7:40.0
2:00.0203 W8:00.0
2:05.0179 W8:20.0
2:10.0159 W8:40.0
2:15.0142 W9:00.0
2:20.0128 W9:20.0
2:25.0115 W9:40.0
2:30.0104 W10:00.0

FAQ

About splits and watts.

How do you convert watts to a split on the erg?
With Concept2's formula backwards: split /500 m = 500 × ∛(2.80 ÷ watts). 300 W is a 1:45.3 and 200 W a 2:00.5. It's what the PM5 does when you switch the display from split to watts, and what this calculator does.
Why does every second off the split get harder?
Because watts grow with the cube of speed: the water (and the erg's fan) pushes back harder the faster you go. Going from 2:00 to 1:55 takes 13% more power; from 1:35 to 1:30, almost 18%.
What are watts per kilo for?
To compare rowers of different weights. On the erg body weight doesn't slow you down, so heavier rowers have an edge; W/kg removes it and says more about what that rower will move in the boat. In Remonta Performance they're worked out for every session, with that day's weight.

Split, watts and W/kg for every stroke, no calculator needed.

With Remonta Performance the PM5 connects to the app: the athlete rows today's session and the coach follows the whole squad's splits and watts live.

See Remonta Performance Book a demo

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