Pace calculator: MAS, easy pace, threshold and predicted times
Enter your MAS (max aerobic speed) or a recent race time and get your training paces: easy running, marathon pace, threshold, 10K pace, intervals, with heart-rate ranges, and your predicted times from 5K to marathon.
Last updated: 2026-09-28
These paces, straight on your watch
Free · official Garmin connection · workouts sent to your watch
The calculator
Enter your MAS (maximal aerobic speed), in km/h or mph, and your maximum heart rate if you know it. If you have never measured your MAS, open "estimate from a recent race" and give a time over 5K, 10K, half or marathon. Everything is computed in your browser.
Measured with a 6-minute test, or estimated from a recent race below.
To show the heart-rate range of each zone.
I don't know my MAS: estimate it from a recent race
Estimate for a trained runner: 5K at 95% of MAS, 10K at 90%, half at 85%, marathon at 79%.
| Zone | % VMA | Pace | Heart rate |
|---|
Predicted times from your MAS
Ballpark figures for a runner trained for the distance. The marathon also needs the mileage: without long runs, the real time will be slower.
These paces can land straight on your watch: your AI coach uses them for every workout it builds.
Connect my GarminTry it with your own Garmin
Free, nothing to install: connect your Garmin, then ask Claude or ChatGPT for your first workout. It lands on your watch within a minute.
How these paces are computed
Each training pace is a percentage of MAS, the speed at which your oxygen uptake is maximal, sustainable for about six minutes. The percentages used here are those of Running Workout's training plans, consistent with the training literature: easy running 60–70%, steady 75–80%, marathon pace 78–82%, threshold 85–88%, 10K pace 90–92%, short intervals 100–105%.
Heart-rate ranges are given as a percentage of max HR: 65–75% for easy running, 86–91% at threshold. They matter most on easy runs, where pace varies with terrain and fatigue: heart rate tells the truth about the effort.
Predicted times assume a runner trained for the distance: 5K at 95% of MAS, 10K at 90%, half marathon at 85%, marathon at 79%. A runner fast over 10K but without long runs will run their marathon slower than predicted: MAS sets the ceiling, mileage sets how much of it you keep over the distance.
Example: MAS 16 km/h
| Zone | % MAS | Pace | Use |
|---|---|---|---|
| Easy running | 60–70% | 6:15 to 5:21 /km | Most of the mileage, long runs |
| Marathon pace | 78–82% | 4:48 to 4:34 /km | Marathon-specific blocks |
| Threshold | 85–88% | 4:25 to 4:16 /km | Tempo, 2 × 15 min, 3 × 10 min |
| 10K pace | 90–92% | 4:10 to 4:04 /km | 5 × 1,000 m, 3 × 2,000 m |
| MAS | 100–105% | 3:45 to 3:34 /km | 30/30, 200 m, 400 m |
With a MAS of 16 km/h, predicted times are about 19:45 for 5K, 41:40 for 10K, 1:33 for the half and 3:20 for the marathon, provided you trained for each distance.
Measure your MAS rather than estimate it
Estimating from a race time is accurate to about ±0.5 km/h, which shifts paces by 10 to 15 seconds per kilometre. For a reliable value, do the 6-minute test: after a full warm-up, run the longest possible distance in 6 minutes on a track or a measured flat stretch; MAS in km/h is that distance in metres divided by 100. Running Workout knows this test: ask your assistant, the workout lands on the watch, and your MAS updates after the run.
Once MAS is known, these paces become concrete targets on the watch: every workout sent by your assistant uses them, and Garmin alerts you when you drift out.
Frequently asked questions
What pace for easy running?
Between 60 and 70% of your MAS, about 65 to 75% of your maximum heart rate. For a MAS of 15 km/h, that is 6:40 to 5:43 per kilometre. At that pace you can speak in full sentences.
How do I compute MAS from a 10K?
A trained runner races 10K at about 90% of MAS. Divide your average 10K speed by 0.90: 48 minutes is 12.5 km/h on average, so a MAS of about 13.9 km/h. The calculator does it for you, for 5K, half and marathon too.
Why is my marathon time far from the prediction?
Because the marathon depends as much on mileage as on MAS. Without regular long runs and marathon-pace blocks, the body cannot hold 79% of MAS for over three hours. The prediction stays right as the goal of a complete 12-to-16-week plan.
Do these paces hold for trail running?
Not as paces. On trails, elevation makes pace unusable: keep the heart-rate ranges, which stay valid, and work by time rather than distance.
These paces, straight on your watch
Connect your Garmin: your AI coach computes your paces from your real runs and sends every workout to the watch.
Get started