Tool · Physiology
MAS calculator (maximal aerobic speed)
Estimate your maximal aerobic speed (MAS, or vVO₂max) from a recent race, a 6-minute half-Cooper test or a progressive stage test. You also get your VO₂max, your VDOT, your 7 pace zones and your predicted race times, all calculated with the Jack Daniels method that powers RunMorph plans.
VDOT is a performance index (Jack Daniels method), deliberately lower than the raw VO₂max estimated from MAS × 3.5, because it factors in your running economy. All of these values are estimates and are no substitute for a lab test.
Show my 7 pace zones
| Zone | Pace |
|---|---|
| Z1 · Active recovery | 12:17 to 14:45 /mi |
| Z2 · Easy aerobic | 10:32 to 12:17 /mi |
| Z3 · Tempo / steady | 9:13 to 10:32 /mi |
| Z4 · Anaerobic threshold | 8:11 to 9:13 /mi |
| Z5 · MAS / VO₂max | 7:01 to 8:11 /mi |
| Z6 · Anaerobic capacity | 6:09 to 7:01 /mi |
| Z7 · Max neuromuscular power | 4:55 to 6:09 /mi |
How to calculate your MAS
Your MAS (maximal aerobic speed, also known as vVO₂max) is the speed at which you reach your maximal oxygen uptake (VO₂max). It’s the baseline for setting all your training paces. Three methods let you estimate it without a lab:
1. From a race time (VDOT method, the most reliable)
Start from a recent performance over a known distance. Jack Daniels’ VDOT model derives your equivalent VO₂max, then your MAS. It’s the calculator’s default method. Example: a 10K in 50:00 (7.5 mph on average) gives a MAS of about 8.1 mph (13.1 km/h), a pace at MAS close to 7:22/mi.
2. The half-Cooper test (6 minutes)
Run all-out for 6 minutes, ideally on a 400 m track, and measure the distance covered:
Example: 1,450 m in 6 minutes → MAS = 1,450 ÷ 100 = 14.5 km/h, or 9.0 mph.
3. A progressive stage test (VAMEVAL, Léger-Boucher)
Stage tests are progressive field tests paced by a soundtrack of beeps. You run around a track marked with cones and must reach each cone on the beep. The speed goes up in regular stages until you can no longer keep up: the speed of the last stage you fully completed is your MAS. That’s their appeal: they measure MAS directly, with no race time and no formula.
- VAMEVAL (developed by Georges Cazorla): cones every 20 m, starting at 8 km/h, then +0.5 km/h every minute. Small increments and close cones make it the most precise stage test, and the one running clubs use most.
- Léger-Boucher: cones every 50 m, starting around 8 km/h, then +1 km/h every 2 minutes. Older and a little less fine-grained (longer, more widely spaced stages), but the principle is the same.
Either way, enter the speed of your last completed stage in the calculator. If you stop mid-stage, use the previous one. These tests are usually run on a track, at a running club, with the official soundtrack. Don’t confuse them with the 20 m shuttle run (the “beep test”), which is mainly designed to estimate VO₂max.
Whatever the method, the pace for a given speed is pace (min/mi) = 60 ÷ speed (mph).
MAS chart: training paces
Key paces based on your MAS, as a percentage of it. Common benchmarks: ~100% for short intervals, ~90% close to 10K pace, ~85% for the half, ~80% for the marathon, ~70% for easy running.
| MAS | 100% (intervals) | 90% (≈ 10K) | 85% (≈ half) | 80% (≈ marathon) | 70% (easy) |
|---|---|---|---|---|---|
| 7.5 mph | 8:00 /mi | 8:53 /mi | 9:25 /mi | 10:00 /mi | 11:26 /mi |
| 8 mph | 7:30 /mi | 8:20 /mi | 8:49 /mi | 9:23 /mi | 10:43 /mi |
| 8.5 mph | 7:04 /mi | 7:51 /mi | 8:18 /mi | 8:49 /mi | 10:05 /mi |
| 9 mph | 6:40 /mi | 7:24 /mi | 7:51 /mi | 8:20 /mi | 9:31 /mi |
| 9.5 mph | 6:19 /mi | 7:01 /mi | 7:26 /mi | 7:54 /mi | 9:01 /mi |
| 10 mph | 6:00 /mi | 6:40 /mi | 7:04 /mi | 7:30 /mi | 8:34 /mi |
| 10.5 mph | 5:43 /mi | 6:21 /mi | 6:43 /mi | 7:09 /mi | 8:10 /mi |
| 11 mph | 5:27 /mi | 6:04 /mi | 6:25 /mi | 6:49 /mi | 7:48 /mi |
| 11.5 mph | 5:13 /mi | 5:48 /mi | 6:08 /mi | 6:31 /mi | 7:27 /mi |
| 12 mph | 5:00 /mi | 5:33 /mi | 5:53 /mi | 6:15 /mi | 7:09 /mi |
These paces are percentage-of-MAS benchmarks. The calculator above refines your 7 zones with the VDOT method from your actual race time.
Frequently asked questions
What is MAS in running?
MAS (maximal aerobic speed, also called vVO₂max) is the running speed at which your body uses the most oxygen it can (your VO₂max). It’s a reference speed: expressed in mph or km/h, it gives you every training pace, from easy runs to intervals. Most runners can hold their MAS for about 4 to 6 minutes at maximal effort.
How can I work out my MAS without a lab test?
Three simple methods: (1) from a recent race time (5K, 10K, half…), using Jack Daniels’ VDOT index, the most reliable; (2) with the half-Cooper test: run all-out for 6 minutes, and MAS (km/h) = distance covered in meters ÷ 100; (3) with a stage test such as VAMEVAL or Léger-Boucher, where the speed of the last stage you complete is your MAS. This calculator handles all three.
What’s the difference between MAS and VO₂max?
VO₂max is an oxygen uptake (in ml/kg/min); MAS is the running speed at which you reach it. You go roughly from one to the other with VO₂max ≈ MAS (km/h) × 3.5. VDOT, on the other hand, is a performance index that factors in your running economy: it sits a little below raw VO₂max.
What is MAS used for in training?
It sets the intensity of every session. Common benchmarks: easy running at about 60-70% of MAS, marathon pace around 80%, threshold around 85-90%, and short intervals between 95 and 105%. Knowing your MAS stops you from running your easy days too fast and your hard sessions too soft.
How often should I recalculate my MAS?
Every 6 to 10 weeks, or after a benchmark race. MAS improves with training (especially for newer runners), then levels off; recalculating it regularly lets you adjust your paces so you keep improving without getting hurt.
Turn your MAS into a training plan
RunMorph works out your 7 training paces from your MAS and builds a session-by-session plan, periodized all the way to race day.
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