VO2 Max Calculator
A 2k erg time, or any longer piece, is enough to estimate your VO2max. Useful for setting zones and following aerobic progress between lab tests across an Irish season.
How do you estimate VO2max from rowing?
Two options. Put a 2k time into the Klusiewicz formula (-0.0224 x seconds + 91.3 for men, -0.0245 x seconds + 95.5 for women). Or take any piece, read average watts off the Concept2 power equation, divide by body weight in kg, and finish with the ACSM rowing formula (VO2 = 12.5 x W/kg + 3.5). Each returns millilitres of oxygen per kilogram of body weight per minute, usually inside 5 ml/kg/min of a lab test.
Your test
Klusiewicz published one equation for men and another for women, each validated on its own group. Choosing "Other" applies the male equation.
No age term appears in either equation. It only frames the bands.
Test summary
Estimated VO2max
ml/kg/min
Method
Average power
One field test gives one estimate. A lab assessment - mask, gas analyser, ramp protocol - is still the reference standard, and field numbers tend to land 3-5 ml/kg/min either side of it.
Where you sit against rowing benchmarks
Band boundaries follow ACSM Guidelines for Exercise Testing and Prescription (11th ed.) together with Hagerman 1984 measurements on national team oarsmen and oarswomen. Elite men routinely test above 70 ml/kg/min, elite women above 60.
Worked example
A club rower of 75 kg, male, records 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 lands in the elite band, generous for a 6:50 club 2k, so treat it as the top of the range.
- 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.
Neither number is wrong; they answer slightly different questions. Klusiewicz was built on elite data and reads high below that level. The ACSM route reads low, because a single fixed efficiency is applied to every rower. Around 60-65 ml/kg/min is the realistic answer here.
How the estimate works
What VO2max is, and why rowers care
VO2max describes the greatest amount of oxygen you can take in, carry and use at full effort, reported as millilitres per kilogram of body weight per minute. Rowing draws heavily on the aerobic system - roughly 75% of a 2k - so VO2max limits the power you can hold. Coaches in clubs on the Lee, the Liffey and the Shannon use it to set zones, follow aerobic gains through the season, and flag juniors worth putting forward for Rowing Ireland development squads.
Estimating from a 2k time (Klusiewicz)
Klusiewicz and colleagues measured VO2max directly in Polish national team rowers, then fitted linear equations to 2k erg time in seconds. Men: VO2max (ml/kg/min) = -0.0224 x T + 91.3. Women: VO2max = -0.0245 x T + 95.5. With a negative coefficient, a lower T - a quicker 2k - returns a higher figure. Their group was elite, so club and recreational rowers get generous answers. Read the output as an upper bound.
Estimating from any test piece (Concept2 + ACSM)
Any piece can be reduced to average power with the Concept2 formula: watts = 2.80 / (pace_in_seconds_per_metre)^3. Dividing by body weight in kg gives W/kg. The ACSM rowing equation - Hagerman 1984, later part of the ACSM Guidelines for Exercise Testing - puts an oxygen cost on that: VO2 (ml/kg/min) = 12.5 x W/kg + 3.5. Mechanical efficiency is held at around 20%, reasonable on average though individuals differ. For a maximal effort of 5 to 30 minutes the result approximates VO2max.
How accurate is the estimate?
In trained rowers a field estimate normally sits within 5 ml/kg/min of the lab value. Klusiewicz runs high below elite level, since its validation group was the Polish national team. The ACSM power equation runs slightly low, because real efficiency usually beats the 20% assumed. If the two agree inside 5 ml/kg/min, work from the estimate. If they differ by more than 10, the lower one is generally the safer bet.
Use this with the other Row HQ tools
The rest of the toolkit builds on this. Send your 2k to the 2k prediction calculator for longer-distance equivalents. The training pace calculator returns UT2, UT1, AT, TR and AN zone splits from the same time. The rowing pace chart sets pace, watts and split side by side for every common distance.
Two more worth a look: the rowing to running converter applies this VO2 model across sports to match erg and road paces, and the data-driven training guide covers tracking the figures across a season.
Frequently asked questions
Why is estimated VO2max from rowing reasonably accurate?
Rowing puts more muscle to work than almost any other tested sport - legs, back and arms together - so oxygen delivery, not a single muscle group, becomes the limit. The Concept2 erg adds a clean, repeatable power reading on top of that. A maximal piece therefore stands in reasonably well for whole-body VO2max, with field and lab values normally within 5 ml/kg/min, much like a 1.5-mile running trial.
Why does the formula differ by sex?
The two equations were validated on separate groups because average physiology differs: heart size, haemoglobin and body composition all shift the relationship between pace and oxygen cost. A 60 kg woman on 7:00 for 2k is working nearer her ceiling than a 90 kg man on the same time, which is why the coefficients differ. The Other option applies the male equation, since no validated alternative exists yet for intersex or non-binary rowers.
How does my number compare to elite Irish rowers?
Elite heavyweight men regularly test above 70 ml/kg/min and the strongest international scullers pass 80. Elite heavyweight women commonly sit 60-65, with the best above 70. Ireland has produced world and Olympic medallists in both lightweight and open categories, so the top of the domestic range reaches international level. Fit club rowers usually sit 50-60 (men) or 45-55 (women), and recreational members 35-45.
Should I get a lab VO2 test instead?
The lab is worth it when the baseline has to be exact: entering a Rowing Ireland development squad, joining a research project, or committing to a big change in your programme. Ordinary training weeks do not call for it. Repeat the same 2k or 6k on the same erg every 8-12 weeks, enter the time here, and watch the trend. A gain of 3-5 ml/kg/min over a winter block is real adaptation.
Does my 2k time predict marathon erg time?
Only indirectly. VO2max sets the aerobic ceiling, while a marathon erg is decided mainly by lactate threshold - the quickest pace you can hold steady - plus muscular endurance and fuelling. Two rowers on the same VO2max can finish far apart over two hours, depending on how close to that ceiling each can live. Use the 2k prediction calculator up to 30 minutes; beyond that, test the distance itself.
How does this differ from heart rate-based VO2 estimates?
Fitness watches work from the relationship between heart rate and submaximal pace, which is a longer chain and a less reliable one. It suits rowers badly: heart rate at a given power sits lower on the erg than running, because of the seated position and the pump from the leg drive. The power-based methods here go from mechanical output to oxygen cost and skip 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.
For one rower VO2max is a sum. For a squad of thirty it needs a system.
Thirty rowers through a winter base block means every 2k and 6k logged, dated and trended before any of it tells you much. Row HQ keeps that together in coach tools and training session tracking. Pair the VO2max estimate with the training pace calculator and each rower gets zone splits set individually, with no shared spreadsheet to maintain.
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.