VO2 Max from Race Time Calculator (Daniels)

VO2 Max from Race Time (Daniels Formula)

The Daniels Running Formula uses a single race time to estimate VO2 max-equivalent fitness (called VDOT in his system) and predict times at other distances.

The Daniels formula: Velocity (m/min) = Distance (m) / Time (min) %VO2max = 0.8 + 0.1894393 × e^(-0.012778 × T) + 0.2989558 × e^(-0.1932605 × T) VO2 = -4.6 + 0.182258 × velocity + 0.000104 × velocity² VDOT = VO2 / %VO2max

Where T is time in minutes for the race.

Why VDOT is useful:

• Single fitness number (around 30-85 for most runners)
• Calculate equivalent times at other distances
• Set training paces (easy, tempo, intervals, repetitions)
• Track fitness changes over time

VDOT-to-race-time mapping

Every row below comes straight out of the formula above rather than from a rule of thumb, so a runner sitting on any one of these times sits on all four:

The marathon column is worth a second look, because it is where most published VDOT tables get quoted wrong. A 3:30 marathon is not a VDOT of 55, which is what you often see claimed. It is about 44, the same fitness as a 22-minute 5K. A sub-3:00 marathon is around VDOT 53, not 60. The 5K and the marathon feel wildly different, and the formula is unsentimental about how much slower marathon pace really is.

Why VDOT predictions might miss:

• Recent training mismatch: if you trained for 5K, half marathon time will be optimistic
• Heat / elevation: Daniels assumes ideal conditions; hot races are 2-5% slower
• Course terrain: hilly, technical courses skew predictions
• Fueling: bonking ruins long-distance times (especially marathon)
• Pacing strategy: even-paced races match VDOT prediction; positive splits don’t

Using VDOT for training: Daniels uses VDOT to set training paces:

This lets you train in the right zones for VO2 max improvement without guesswork.

Lab VO2 max vs. predicted VDOT: Direct lab testing (graded treadmill or cycling) measures actual VO2 max in mL/kg/min. VDOT is race-derived. It folds running economy, lactate threshold, and aerobic capacity into one number. They correlate well but VDOT is more practical for non-lab settings.