VO2 Max Calculator
Estimate your VO2max from a 2k erg time, or from any longer test piece. Useful for setting training zones and tracking aerobic progress between lab tests.
How do you estimate VO2max from rowing?
Two methods. From a 2k time, use the Klusiewicz formula (-0.0224 x seconds + 91.3 for men, -0.0245 x seconds + 95.5 for women). From any test piece, work out average watts using the Concept2 power equation, divide by body weight in kg, then apply the ACSM rowing formula (VO2 = 12.5 x W/kg + 3.5). Both give ml of oxygen per kilogram of body weight per minute. Estimates typically land within 5 ml/kg/min of a lab test.
Your test
The Klusiewicz formula was validated separately on male and female rowers. The "Other" option uses the male formula by default.
Not used in the formula. Shown for benchmark comparison.
Test summary
Estimated VO2max
ml/kg/min
Method
Average power
This is an estimate from a single field test. Lab VO2 testing (mask, gas analyser, ramp protocol) remains the gold standard and typically lands within 3-5 ml/kg/min of these field estimates.
Where you sit against rowing benchmarks
Bands adapted from ACSM Guidelines for Exercise Testing and Prescription (11th ed.) and Hagerman 1984 data on US national team oarsmen and oarswomen. Elite rowers regularly test above 70 ml/kg/min for men and 60 ml/kg/min for women.
Worked example
A 75 kg male club rower pulls a 2k in 6:50.0 (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: that number sits in the elite range, which fits a 6:50 2k for a heavyweight club rower in good shape.
- 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.
The two methods give different numbers because they measure different things. Klusiewicz over-predicts for sub-elite club rowers; ACSM under-predicts because it assumes 100% mechanical efficiency. Real VO2max for this rower is likely around 60-65 ml/kg/min - between the two estimates.
How the estimate works
What VO2max is, and why rowers care
VO2max is the maximum volume of oxygen your body can take in, transport, and use during all-out exercise. It is expressed in millilitres of oxygen per kilogram of body weight per minute. Rowing is heavily aerobic - even a 2k is roughly 75% aerobic - so VO2max sets the ceiling on how much power you can sustain. Coaches use it to set training zones, track aerobic adaptation over a season, and predict race potential.
Estimating from a 2k time (Klusiewicz)
Klusiewicz and colleagues tested Polish national team rowers in the lab and built simple linear formulas relating 2k erg time (in seconds) to lab-measured VO2max. Men: VO2max (ml/kg/min) = -0.0224 x T + 91.3. Women: VO2max = -0.0245 x T + 95.5. The negative coefficient means a faster 2k (lower T) gives a higher VO2max. The formulas were calibrated on competitive rowers, so for club and recreational rowers they tend to over-predict. Treat them as a ceiling, not a measurement.
Estimating from any test piece (Concept2 + ACSM)
Any test piece gives you average power via the Concept2 formula: watts = 2.80 / (pace_in_seconds_per_metre)^3. Divide by body weight in kg to get W/kg. The ACSM rowing equation (Hagerman 1984, adopted by ACSM Guidelines for Exercise Testing) converts that to oxygen consumption: VO2 (ml/kg/min) = 12.5 x W/kg + 3.5. This assumes a constant mechanical efficiency of about 20%, which is a reasonable average but varies between athletes. For a maximal test of 5-30 minutes, the resulting VO2 is a fair approximation of VO2max.
How accurate is the estimate?
Field estimates of VO2max from rowing performance typically land within 5 ml/kg/min of lab-measured values for trained athletes. The Klusiewicz formula tends to over-estimate for sub-elite rowers because it was calibrated on the Polish national team. The ACSM power formula tends to under-estimate because it assumes a constant 20% mechanical efficiency, which most athletes exceed slightly. If both methods agree to within 5 ml/kg/min, you can trust the estimate. If they disagree by more than 10, the lower number is usually closer to truth.
Use this with the other Row HQ tools
Once you have an estimated VO2max, plug your 2k time into the 2k prediction calculator to see how it scales to longer distances. Use the training pace calculator to derive UT2, UT1, AT, TR and AN zone paces. Use the rowing pace chart to map pace, watts and split across every common distance.
Frequently asked questions
Why is estimated VO2max from rowing reasonably accurate?
Rowing is one of the most aerobic sports tested. The Concept2 ergometer gives a clean, repeatable power output, and rowing recruits a large fraction of total muscle mass (legs, back, arms), so the cardiovascular system is genuinely the limiter. That makes a maximal rowing test a fair proxy for whole-body VO2max. Field estimates from rowing typically agree with lab values to within 5 ml/kg/min, which is similar to running estimates from a 1.5-mile time trial.
Why does the formula differ by sex?
Klusiewicz validated his formula separately on male and female rowers because women have, on average, smaller hearts, lower haemoglobin, and a different body-composition baseline. A 7:00 2k for a 60 kg woman represents a much higher relative effort than the same time for a 90 kg man, so the formulas use different coefficients. The Other option in the calculator defaults to the male formula because intersex and non-binary rowers tend to have varied physiology and there is no validated formula yet. Pick whichever formula best matches your training and body type.
How does my number compare to elite rowers?
Elite male heavyweights regularly test above 70 ml/kg/min, with the top international scullers reaching 80+. Elite female heavyweights typically sit 60-65 ml/kg/min, with the top end above 70. Lightweights tend to test slightly lower in absolute terms but higher relative to bodyweight. Club rowers in good shape usually sit 50-60 (men) or 45-55 (women). Recreational adult rowers often sit 35-45. The bands shown on this page are aligned to those reference points.
Should I get a lab VO2 test instead?
Lab testing is the gold standard if you need an exact baseline (for instance, joining a national squad or being part of a research project). For day-to-day training, a field estimate from a 2k or 6k is plenty accurate. Repeat the same test piece on the same erg every 8-12 weeks, plug the time into this calculator, and look at the trend. A 3-5 ml/kg/min improvement over a winter base block is a strong signal of aerobic adaptation.
Does my 2k time predict marathon erg time?
Indirectly, yes. VO2max predicts the upper aerobic ceiling, but marathon performance is heavily driven by lactate threshold (your highest sustainable steady-state pace), muscular endurance, and fuelling. A higher VO2max raises the room available above threshold, but two rowers with the same VO2max can have very different marathon times depending on how close to that ceiling they can sit for 2 hours. Use the 2k prediction calculator for distances up to 30 minutes; beyond that, marathon-specific testing is more reliable.
How does this differ from heart rate-based VO2 estimates?
Heart rate methods (used by some fitness watches) estimate VO2max from the relationship between heart rate and submaximal pace - a less direct route. They tend to be less accurate for rowers because rowing heart rate at a given power is lower than running heart rate, due to the seated position and large muscle pump. Power-based methods like the ones used here are more direct for rowing because they bypass heart rate entirely.
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.
Tracking VO2max for one rower is a calculation. Tracking it for an entire squad is a system.
A coach who wants to monitor aerobic progress for 30 rowers across a winter base block needs every 2k and 6k result logged, dated, and trended. That is what Row HQ does inside coach tools and training session tracking. Pair the VO2max estimate with the training pace calculator to set individual zones for every rower 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.