Running Training Pace Calculator
This calculator works out your personal training paces for running by converting a recent race result, or your heart rate figures, into five clear effort zones you can train by. Enter the distance and time of a recent race, from a 1 km time trial up to a marathon, and it applies the Jack Daniels VDOT method to set a target pace per kilometre for each zone. If you would rather work from heart rate, switch methods and enter your maximum heart rate, plus resting heart rate if you know it, so the Karvonen formula can sharpen the ranges. The results table returns a pace or heart rate range for each of the five zones, recovery, aerobic base, moderate, threshold and VO2 max intervals, with a note on when to use each one. Zone 2, your aerobic base, should make up 70 to 80 percent of weekly running and is usually slower than runners expect, which is the point. Use the results to plan a realistic week of easy running, one tempo or threshold session, and one interval session, rather than running every session at a similar hard effort. These paces are estimates based on a single result or heart rate reading, so treat them as a training guide rather than a fixed rule, and adjust for heat, fatigue, terrain and how your body feels on the day.
| Zone | Pace per km | When to use |
|---|
Paces calculated using the Jack Daniels VDOT method.
How it works
When you enter a race result, the calculator converts your finish time to a pace per kilometre, then applies percentage multipliers based on the Jack Daniels VDOT framework. Each training zone runs at a different fraction of race effort. The key insight is that zone 2 running is slower than most people expect: for a runner who races 5 km at 5:00 per kilometre, the zone 2 training pace is 5:30 to 6:00 per kilometre. This feels uncomfortably easy, but that is the point.
When you enter heart rate values, the calculator uses the Karvonen formula if you supply a resting heart rate, which accounts for individual fitness level. Without a resting heart rate it uses simple percentages of your maximum heart rate.
The five training zones
- Zone 1 - Recovery: Warm-ups, cool-downs, and days after hard sessions. Completely conversational, you could sing. Keeps blood flowing without adding stress.
- Zone 2 - Aerobic base: The most important zone. Builds mitochondrial density, improves fat metabolism, and develops the aerobic engine that underpins all other zones. Should make up 70 to 80 percent of all training. You can hold a conversation but would choose not to.
- Zone 3 - Moderate effort: Useful for marathon-pace long runs and progression runs. Harder to speak in full sentences. Use sparingly as it is hard enough to create fatigue but not hard enough to deliver the maximum training stimulus.
- Zone 4 - Threshold: Lactate threshold pace. This is around 10 km race effort for most runners and half-marathon pace for faster runners. Short sentences only. Classic tempo runs and cruise intervals sit here.
- Zone 5 - VO2 max intervals: Maximum effort for 400 m to 1,200 m repeats. Speaking is not possible. Raises your aerobic ceiling. Keep efforts under 5 minutes each with full recovery between.
Worked example
Runner who completed 5 km in 25:00 (pace: 5:00 per km).
- Zone 2 target: 5:30 to 6:00 per km, conversational effort. Use for the majority of weekly mileage.
- Zone 4 tempo target: 4:30 to 4:54 per km, sustained hard effort. Use for one tempo session of 20 to 40 minutes per week.
- Zone 5 intervals: 4:06 to 4:27 per km, maximum effort. Use for 4 to 8 x 400 m or 3 to 5 x 1,000 m once per week.
A well-structured week might include four zone 2 runs and one zone 4 or zone 5 session, with zone 1 warm-ups and cool-downs around each hard effort.
Frequently asked questions
What is zone 2 training and why is it important?
Zone 2 is 60 to 70 percent of maximum heart rate, an aerobic effort where you can hold a conversation. Research shows that spending 70 to 80 percent of training in zone 2 builds the strongest aerobic base and improves fat metabolism, which underpins performance at every distance.
How do I calculate my training paces from a race result?
Enter your recent race time above. The calculator applies the Jack Daniels VDOT method to set each training zone as a percentage of your race pace. Zone 2 runs at roughly 110 to 120 percent of your race pace (slower), while zone 5 intervals run at 82 to 89 percent (faster).
Why do my training paces feel slow?
Zone 2 pace often feels surprisingly slow, especially for newer runners. Running easy most of the time is a key principle of effective training used by elite marathon runners worldwide. Keeping easy days truly easy allows you to train harder on hard days and recover fully between sessions.