Rowing Calorie Calculator

A 70 kg rower holding 100 to 149 watts, a split around 2:21 to 2:32 per 500 m, burns about 276 kcal in 30 minutes and 551 in an hour. A Concept2 monitor would show more for the same piece, about 365 for the half hour, and the gap between those two figures is most of what this page is about. The calculator above uses the Compendium MET value for each wattage band, with the code, and the tables below cover the common cases.

Rowing calorie calculator: calories per hour by erg watts

Compendium codes 02071 through 02074. The split column uses the Concept2 relationship between pace and power, watts = 2.80 / (seconds per 500 m / 500) cubed, so 2:00 is 203 W and 2:32 is about 100 W. By session length, 100 to 149 W band:

The formula

kcal per minute = MET x 3.5 x body weight in kg / 200

For 70 kg in the 100 to 149 W band: 7.5 x 3.5 x 70 / 200 = 9.19 kcal per minute, 276 in 30 minutes, 551 an hour. Code 02072.

What the Concept2 monitor is doing

The erg is the one machine in the gym that measures your work properly. The flywheel's deceleration between strokes tells the monitor the drag, and from drag and flywheel speed it computes watts, which is why a Concept2 split is trusted across the sport in a way a spin bike's resistance dial never is. But the calorie figure on the monitor is not measured. It is a formula: kcal per hour = 4 x watts x 0.8604 + 300, and Concept2 says openly that it assumes a 175 lb, or 79 kg, person. It cannot know your weight and does not ask.

Put 125 W into that and you get 730 kcal an hour, 365 for a half hour. The MET route gave 551 and 276 for a 70 kg rower. A third apart, for the same piece, and neither is a measurement. The physics sits nearer the lower figure: 125 W for an hour is 450 kJ, or 108 kcal, of mechanical work, and at a rowing efficiency of about 20 percent that is roughly 540 kcal gross. The monitor's formula is generous, which is fine as long as you use it only to compare your own sessions on the same machine, and the erg calculator works that formula alongside split, watts and pace if you want it.

Body weight is the other wrinkle. The MET table scales with weight because a 90 kg person carries 90 kg when they walk. On an erg nobody carries anything, so two rowers at the same 150 W are doing the same work and burning roughly the same calories, and the table's weight columns overstate the spread. In practice the columns and the watts agree more than that suggests, since heavier rowers tend to hold more watts. If you have the watts, trust the watts times about 3.5 for an hourly estimate, and use the table when you only know the effort.

The table is an average, and it is gross

A MET value describes an average person of that weight rowing in that band, and the 3.5 ml/kg/min resting rate it multiplies is itself an average that runs high for many heavier and older adults. Technique matters more on the erg than almost anywhere: a rower who slumps at the catch and yanks with the arms spends more oxygen for the same split than one who drives with the legs, and a 10 to 15 percent spread between people at the same watts is normal. The heart-rate estimate from a wrist device adds another layer, and wrist devices have missed energy expenditure by a quarter or more in independent tests. Call it a band, plus or minus 20 percent, on every source including this one.

The figure is gross. It includes the roughly 74 kcal an hour a 70 kg person spends alive. Subtract 1 from the MET for the net cost before you eat the session back, and see the calories burned calculator for the gross and net sum written out.

Where the number goes

An erg piece is one line in the day's budget. Set the budget with the TDEE calculator and size the cut with the calorie deficit calculator. The bike next to the erg has its own page, the stationary bike calorie calculator, with the same watts logic, and the MET calculator carries the full set of 46 values including the swimming and strength rows.

How Movement Rebels fits

Movement Rebels connects to Concept2 directly. Your erg sessions sync in with their duration and their measured watts, which no calculator page can offer because a calculator does not know what you rowed. The coach reads those sessions as training load when it plans your week, alongside anything from Garmin Connect or Apple Health, and reads the erg piece you did rather than an average person's version of it.

The coach cannot see your food. Rebel Fuel is your own log and nothing from it reaches the coach, so it will not compare what you ate with what you rowed. If you are in a deficit, say so in the notes for your coach, and it will treat a rising resting heart rate or a falling HRV as a fuelling signal rather than a fitness drop. For keeping strength and power while the scale moves, read Training on a Calorie Deficit.

MET values used here

Every value below is quoted from the Compendium of Physical Activities with its activity code, so you can look up the entry yourself. One MET is the oxygen cost of sitting quietly, about 3.5 ml of oxygen per kg per minute.

Walking and hiking

Treadmill walking

Running

Curved (non-motorised) treadmill running

Cycling

Stationary cycling

Rowing machine

Swimming

Strength and gym

Source: Compendium of Physical Activities (Ainsworth et al.), pacompendium.com. Codes are the Compendium's own.

Questions

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