VO2 Max Calculator
Put in a 2k erg time, or any longer piece, and get a VO2max figure back. Enough to set training zones and follow aerobic gains from winter base through to Maadi Cup in March.
How do you estimate VO2max from rowing?
Two ways in. A 2k time goes straight through the Klusiewicz formula (-0.0224 x seconds + 91.3 for men, -0.0245 x seconds + 95.5 for women). Any other piece starts with average watts from the Concept2 power equation, divided by body weight in kg, then finished with the ACSM rowing formula (VO2 = 12.5 x W/kg + 3.5). Both report millilitres of oxygen per kilogram per minute, normally within 5 ml/kg/min of a lab figure.
Your test
Separate validations were run on men and women, so each sex carries its own coefficients. "Other" uses the male equation.
The maths does not use age. It is here so the reference bands read more sensibly.
Test summary
Estimated VO2max
ml/kg/min
Method
Average power
This is one estimate off one field test. Lab work - mask, gas analyser, ramp protocol - stays the reference method, and field figures normally sit 3-5 ml/kg/min from it.
Where you sit against rowing benchmarks
Band edges come from ACSM Guidelines for Exercise Testing and Prescription (11th ed.) plus Hagerman 1984 measurements on national team oarsmen and oarswomen. Above the top band, elite men usually read past 70 ml/kg/min and elite women past 60.
Worked example
Say a 75 kg male club rower goes 6:50.0 for 2k on the erg. That is 410 seconds.
- 1.Convert time to seconds: 6 minutes 50 seconds = 410 seconds.
- 2.Apply Klusiewicz male formula: VO2max = (-0.0224 x 410) + 91.3.
- 3.Calculate: -9.184 + 91.3 = 82.1 ml/kg/min.
- 4.Sense-check: 82.1 falls inside the elite band, flattering for a 6:50 club 2k, so hold it as an upper limit.
- 5.Cross-check with the power method: a 6:50 2k = 270 W average = 3.60 W/kg, giving 12.5 x 3.60 + 3.5 = 48.5 ml/kg/min.
Both figures are right for what they measure, which is why they disagree. Klusiewicz sits high for anyone below elite level. The ACSM route sits low, because it prices every stroke at one fixed efficiency. Somewhere near 60-65 ml/kg/min is the realistic number for this rower.
How the estimate works
What VO2max is, and why rowers care
VO2max is the most oxygen your body can draw in, move and use when you are going flat out, quoted in millilitres per kilogram of body weight per minute. Because rowing is so aerobic - roughly three-quarters of the energy in a 2k - VO2max fixes the ceiling on sustainable power. Everything below that ceiling is trainable, which is why a rising VO2max usually shows up first as an easier steady state rather than a faster 2k. Coaches at Rowing New Zealand clubs and secondary school programmes use it to set individual zones, check that winter base is paying off, and shape crew selection before Maadi Cup at Lake Karapiro. Tracked over a season it also flags the rower whose form has stalled while everyone else is still moving.
Estimating from a 2k time (Klusiewicz)
Klusiewicz and colleagues lab-tested Polish national team rowers, then fitted straight lines from 2k erg time in seconds to measured VO2max. Men: VO2max (ml/kg/min) = -0.0224 x T + 91.3. Women: VO2max = -0.0245 x T + 95.5. T is seconds, and the minus sign is why a faster 2k gives a bigger figure. Their sample sat at national level, so club and school rowers come out high. Read it as a ceiling, not a measurement.
Estimating from any test piece (Concept2 + ACSM)
Every piece yields average power through the Concept2 formula: watts = 2.80 / (pace_in_seconds_per_metre)^3. Divide by body weight in kg for W/kg. The ACSM rowing equation, from Hagerman 1984 and later adopted into the ACSM Guidelines for Exercise Testing, converts power-to-weight into an oxygen cost: VO2 (ml/kg/min) = 12.5 x W/kg + 3.5. Mechanical efficiency is held at about 20%, sound as an average with real spread around it. On a maximal 5 to 30 minute piece the answer approximates VO2max well.
How accurate is the estimate?
Among trained rowers, field estimates normally land inside 5 ml/kg/min of lab-measured VO2max. Klusiewicz overshoots below elite level, because national squad athletes supplied the validation data. The ACSM power equation undershoots slightly, because most rowers are a shade more efficient than the 20% it assumes. Agreement inside 5 ml/kg/min means the estimate is usable. A gap over 10 usually points to the lower figure being the closer one.
Use this with the other Row HQ tools
Take the estimate further with the rest of the toolkit. The 2k prediction calculator stretches a 2k out to longer distances. The training pace calculator breaks the same time into UT2, UT1, AT, TR and AN splits. The rowing pace chart ties pace, watts and split together across every standard piece.
Also here: the rowing to running converter, which applies this same VO2 model across sports, and the data-driven training guide on using capacity numbers through a full season.
Frequently asked questions
Why is a rowing VO2max estimate reasonably accurate?
Rowing recruits an unusual share of the body - legs, back, core, arms - so the limiting factor really is oxygen delivery rather than one local muscle group. The Concept2 erg then measures power cleanly and repeatably, with no wind, hills or surface to muddy the result the way a running field test does. Put together, an all-out erg piece reads whole-body VO2max well: field and lab values normally agree inside 5 ml/kg/min, which is about as close as any indirect method gets.
Why does the formula differ by sex?
Men and women were validated separately because average physiology differs - heart size, haemoglobin concentration and body composition all shift the relationship. A 60 kg woman holding 7:00 for 2k is working far harder relative to her capacity than a 90 kg man on the same clock, so each sex gets its own coefficients. The Other option uses the male equation, as no validated version exists for intersex or non-binary rowers. Choose the closer fit.
How does my number compare to elite rowers?
Elite heavyweight men usually test above 70 ml/kg/min, with leading international scullers beyond 80. Elite heavyweight women sit mostly 60-65, the best over 70. Lightweights read lower in absolute terms and higher per kilogram, since the number is scaled by body weight. Rowers racing Rowing New Zealand regattas and national university championships tend to span 55-70, depending on the boat class and how many seasons they have behind them. Fit club rowers commonly sit 50-60 (men) or 45-55 (women), and recreational members around 35-45.
Should I get a lab VO2 test instead?
Lab testing earns its cost when the baseline has to be exact - a Rowing New Zealand development programme, a university sports science study, or a serious change in periodisation. Week to week it is not needed. Redo one hard 2k or 6k on the same erg, at the same drag factor and roughly the same time of day, every 8 to 12 weeks. Enter it here and read the trend rather than any single result. Three to five ml/kg/min across a winter block shows the aerobic work is holding.
Does my 2k time predict marathon erg time?
Loosely at best. VO2max sets the roof; a marathon erg is settled by lactate threshold - the fastest pace you can hold steady - along with muscular endurance and fuelling. A bigger VO2max widens the space above threshold, but two rowers on the same number can finish far apart over two hours depending on how close to the roof each can sit. Use the 2k prediction calculator out to 30 minutes and test longer pieces directly.
How does this differ from heart rate-based VO2 estimates?
Watches infer VO2max from how heart rate tracks submaximal pace, which adds an indirect step and its own error. Rowing suffers more than most, because heart rate at a given power runs lower on the erg than on foot, thanks to the seated position and the venous return from the leg drive. A watch tuned on running data therefore reads a rower low. The methods here convert measured power straight into an oxygen cost, with no heart rate involved at all.
Sources
Formulas and benchmark bands were last verified on 17 May 2026.
- Klusiewicz A., Faff J., Starczewska-Czapowska J. (2014). Prediction of maximal oxygen uptake from indirect ergometric tests in highly trained junior rowers. Biology of Sport, 31(2), 105-110. The original validation of the 2k-time-to-VO2max linear formula.
- Klusiewicz A., Borkowski L., Sitkowski D., Burkhard-Jagodzinska K., Szczepanska B., Ladyga M. (2016). Indirect methods of assessing maximal oxygen uptake in rowers. Biology of Sport, 33(4), 333-340. Re-validation across a wider rower population, including women.
- Hagerman F. C. (1984). Applied physiology of rowing. Sports Medicine, 1(4), 303-326. The foundational power-to-VO2 relationship used in the ACSM equation.
- American College of Sports Medicine. ACSM Guidelines for Exercise Testing and Prescription, 11th edition (2021). Wolters Kluwer. The ACSM rowing VO2 equation and adult VO2max reference bands.
- Concept2 (n.d.). Watts calculator and pace-power conversion. Concept2 Indoor Rower documentation. concept2.com/training/watts-calculator. The P = 2.80 / pace^3 formula used for power calculation.
One rower makes this a sum. A full squad through winter makes it a system.
Thirty rowers, a winter base block, and every 2k and 6k needing to be logged, dated and trended - that is the coaching load Row HQ carries inside coach tools and training session tracking. Send the VO2max estimate through the training pace calculator and every rower ends up with their own zone splits, set automatically.
More rowing tools
2k Prediction Calculator
Predict your 2k time from 5k, 6k or 30-minute test results.
Training Pace Calculator
UT2, UT1, AT, TR and AN zone paces from your 2k.
Erg Score Calculator
Weight-adjusted, age-graded percentile ranking.
Bodyweight-Adjusted Erg Score
Compare lightweight and heavyweight 2k times fairly.