Quick answer: 2,400 m in a Cooper 12-minute run estimates a VO2 max of 42.4 ml/kg/min. A 1.5-mile run in 12:00 gives 43.8, and a 25:00 5K gives a VDOT (a running VO2 max estimate) of 38.3.
How to use the VO2 max calculator
Choose the test you did, then fill in its box; the other boxes are ignored. For the Cooper test, run as far as you can in exactly 12 minutes on a track or a measured flat course and enter the distance in miles or km. For the 1.5-mile test, run the distance as fast as you can and enter the time. For a race, choose the distance and type your official time.
The three formulas
Cooper (1968): VO2 max = (metres - 504.9) / 44.73. Kenneth Cooper compared 12-minute run distances with treadmill tests; the regression above is the one used in later studies that cite him. Each extra 100 m adds about 2.2 ml/kg/min.
1.5-mile run (ACSM): VO2 max = 3.5 + 483 / time in minutes, from ACSM's Guidelines for Exercise Testing and Prescription. 10:00 gives 51.8 and 15:00 gives 35.7.
Race (VDOT): the Daniels and Gilbert (1979) equations turn a race time into VDOT, a VO2 max figure for running that also includes your economy and pacing. VDOT is Jack Daniels' term, used descriptively; this site is not affiliated with him.
Worked example
You covered 3,000 m in 12 minutes. (3,000 - 504.9) / 44.73 = 2,495.1 / 44.73 = 55.8 ml/kg/min. The result tiles also show the 5K and marathon times the Daniels-Gilbert model pairs with that number, as a sense check against your real races.
Limits
These are estimates from all-out runs. Pacing, heat, wind, a soft surface or a lack of practice at the test all pull the number down, and the three methods will not agree exactly for the same person. Only a laboratory test with gas analysis measures VO2 max. Hard maximal tests are not for everyone: if you have a heart condition or are new to exercise, check with a doctor first.
Turn the race result into training paces on the training pace calculator, or see what the same fitness means over other distances on the race time predictor. Prefer a walking or lab-style test? Use the Rockport walk test, Harvard step test or Bruce protocol calculators. Which age formula to trust is compared in the max heart rate formulas guide.
Sources: Cooper (1968), A means of assessing maximal oxygen intake, JAMA; Int J Exerc Sci (2017), 12 weeks of physical training in military recruits, using the Cooper equation; Characterization of female US Marine recruits (2023), ACSM 1.5-mile equation; Daniels and Gilbert (1979) equations, quoted by Larry Simpson. Rules checked . Found a problem? Tell us.
Questions
How do I calculate my VO2 max without a lab?
Use a field test. Run as far as you can in 12 minutes and apply Cooper's formula, (metres - 504.9) / 44.73, or time a 1.5-mile run and use 3.5 + 483 / minutes.
What is the Cooper test?
A 12-minute run for maximum distance, published by Kenneth Cooper in 1968. 2,400 m estimates 42.4 ml/kg/min and 3,000 m estimates 55.8.
Why does my watch show a different VO2 max?
Watches use their own methods, which they do not publish as equations like the ones above. A field test gives a number you can reproduce and compare over time.
Is VDOT the same as VO2 max?
It is an estimate of running VO2 max from a race. Because it is based on performance, two runners with the same lab VO2 max can have different VDOT values.