Cardio Converter

Whatever you type is turned into minutes at the effort you chose. Those minutes are then spent on the other machine at the same effort. That is the whole trick. A conversion chart looks like it is matching work, or distance, or energy. It is matching duration and intensity, because duration and intensity are the only things that survive a change of machine.

The two machines are read at matching points in their bands. A fast runner is compared with a fast rower, not with a slow one, so converting a machine into one the page treats as its equal returns the number you typed rather than a spread around it. The answer is then widened by the width of the target machine's own pace band, half either side, because almost nobody is the same relative level on two machines. Those two steps are the whole range you see: band disagreement first, then the allowance for being better at one thing than the other.

Each machine carries a band of typical rates for a recreationally fit adult at easy, moderate and hard effort. Running runs 134 to 161 m/min easy and 188 to 231 m/min hard, which is 7:28 down to 4:20 per kilometre. The RowErg runs 182 to 273 m/min across the same span, which is 2:45 down to 1:50 per 500 m. Those four rowing edges were chosen because Concept2's own pace-to-watts relation puts them at 78, 127, 179 and 264 watts, and each of those figures lands inside one of the Compendium's stationary rowing brackets. The rowing column is the anchor for the page.

The SkiErg carries the rower's band, because the published gym charts keep the two in one column. The bike erg counts its metres against a 1,000 m split rather than a 500 m one, so at the same power it accumulates about twice the metres a rower does. That is why the charts pair 500 m of rowing with 1,000 m on the bike, and the page uses the same 2:1. Air bike and rope carry bands in their own units, calories on the display and skips per minute, and the rope band edges are the Compendium's own cadence brackets.

The bands are also matched to each other, so that the fast edge of one describes roughly the same person as the fast edge of the next. That matching is what makes a 400 m run at hard effort land either side of the 500 m row the charts pair it with. At easy effort the same page puts the rowing equivalent higher, because easy running is slower relative to easy rowing than hard running is to hard rowing.

These bands are assumptions. They are the largest single source of error on the page, which is why they are written down here rather than buried.

Energy is estimated the standard way, from METs and body mass. One MET is 3.5 ml of oxygen per kilogram per minute, and a litre of oxygen costs roughly 5 kcal, so kcal per minute works out as MET x 3.5 x kilograms / 200. Every MET value below is a published figure from the 2024 Adult Compendium of Physical Activities, read at the activity code named next to it. Nothing is interpolated, smoothed or rounded into place.

Rowing and SkiErg use the stationary rowing codes, which are keyed to watts: 02071 under 100 W is 5.0, 02072 at 100 to 149 W is 7.5, 02073 at 150 to 199 W is 11.0, 02074 at 200 W and above is 14.0. The pace band edges are converted to watts with Concept2's formula and read into those brackets. Bike erg and air bike use the stationary cycling codes at the same wattages: 01218 at 70 to 80 W is 5.8, 01228 at 126 to 150 W is 8.0, 01232 at 151 to 199 W is 10.3, 01240 at 230 to 250 W is 12.5. Where a wattage falls in a gap between two brackets the page takes the lower one, which keeps the estimate conservative. Running uses 12030 at 5.0 to 5.2 mph for 8.5, 12050 at 6 to 6.3 mph for 9.3, 12070 at 7 mph for 11.0 and 12100 at 8.6 mph for 12.5. Rope uses the three cadence codes exactly as published: 15552 under 100 skips a minute is 8.3, 15551 at 100 to 120 is 11.8, 15550 at 120 to 160 is 12.3.

Two of those choices are borrowed rather than measured, and both are borrowed downwards. The Compendium's ski entries are keyed to words rather than watts, 02080 for a ski machine in general at 6.8, 02082 for slow to moderate double poling at 10.5 and 02084 for fast to maximum at 18.0, so they cannot be placed on a pace band the way the rowing codes can. The ski column therefore shows the rowing figures, and at hard effort that is a floor rather than a best guess. There is no fan bike entry at all, so the air bike shows the cycling figures for the same effort, which ignores the fact that your arms are working. With no body mass entered the page uses 79.5 kg, which is Concept2's reference athlete.

A Concept2 monitor does not use METs. It converts your power to calories with a published formula, calories per hour = 4 x watts / 1.1639 + 300, built around a 175 lb athlete with a 300 cal/hour base rate. Power itself comes from pace by watts = 2.80 / pace cubed, with pace in seconds per metre. The page shows both the monitor figure and the MET estimate for the rowing column so you can see the gap rather than pick a side. Concept2 publishes its own weight correction and this page applies it whenever you enter a body mass.

Air bike calories are a different thing again. They are a display unit derived from fan speed, not a measurement of you, and two brands do not scale them the same way. Jump rope has no monitor at all.

It will not tell you which end of a band you sit on. It does not know your fitness, your damper setting, your fan bike's brand, the wind on your run or how you slept, and no calculator that asks six questions does. It will also refuse to hand you a single conversion number, because there is not one to hand over.

If you need a figure you can actually plan a session around, spend one honest minute on the machine at the effort you mean, count what it gives you, and use that instead of anything on this page. The page is for the swap you have to make before you have that minute.

The conversion is finished before any link is considered. A partner appears under the answer only when the machine you converted to is one you told the page you do not own, and only when that partner actually sells it. Nothing about a partner reaches the pace bands, the MET values, the ranges or the table above. If you own the machine, or nobody we work with stocks it, no link renders at all.