Planning a track session? Pick your rep distance, enter the target pace, set the number of reps and recovery type - the calculator builds a series-by-series plan with timed rest intervals based on the work-to-rest ratio for your chosen distance.
Interval Training Calculator - Rep Distance, Pace & Rest Intervals
Planning a track session? Pick your rep distance, enter the target pace, set the number of reps and recovery type - the calculator builds a series-by-series plan with timed rest intervals based on the work-to-rest ratio for your chosen distance.
Parameters
Enter data for calculations
💡 Fill in all required fields to unlock the calculate button
Five distances, three recovery types, one structured plan
This calculator takes four inputs - rep distance, target pace per kilometer, number of repetitions and recovery method - and returns a complete series-by-series interval workout. Rest periods follow the work-to-rest ratio principle: shorter reps get equal rest, longer reps get proportionally less. The result is a table showing each rep's time, the rest after it and a running cumulative clock.
How to use the interval training calculator - step by step
- Rep distance - select between 200 m and 2000 m. Short reps (200-400 m) target raw speed, long reps (1000-2000 m) target lactate threshold.
- Target pace - minutes and seconds - enter the per-kilometer pace you plan to hold during each fast rep. For example, 4 min 30 sec means a 4:30 min/km interval pace.
- Number of reps - set between 2 and 20. Beginners typically run 4-6 reps, advanced runners 8-12.
- Recovery type - choose jog (keeps heart rate elevated), walk (moderate recovery) or standing rest (full recovery).
- Read the results: total workout time, distance, rest duration per interval and a full series-by-series table.
Work-to-rest ratios by distance and recovery type
The calculator uses evidence-based ratios. Shorter reps need relatively more rest (equal time), while longer reps use shorter relative rest because the effort is submaximal.
| Rep distance | Jog recovery | Walk recovery | Standing rest |
|---|---|---|---|
| 200-400 m | 1:1 | 1:0.75 | 1:0.5 |
| 600-800 m | 1:0.75 | 1:0.67 | 1:0.5 |
| 1000-1200 m | 1:0.67 | 1:0.5 | 1:0.4 |
| 1600-2000 m | 1:0.5 | 1:0.5 | 1:0.4 |
Practical examples
When to use each rep distance
| Distance | Trains | Race goal | Typical effort |
|---|---|---|---|
| 200-400 m | Speed, neuromuscular power | 800 m - 1500 m | 90-95% |
| 600-800 m | VO2max, anaerobic capacity | 3 km - 5 km | 85-90% |
| 1000-1200 m | Lactate threshold | 5 km - 10 km | 80-85% |
| 1600-2000 m | Tempo endurance | 10 km - half marathon | 75-80% |
FAQ - Frequently asked questions
Related tools
Running Pace Calculator
Calculate your pace per km or mile from distance and time, with race predictions for 5K through marathon - See calculator
Weather Pace Adjustment Calculator
Adjust your interval pace for heat, humidity, wind and surface conditions - See calculator
Walk-Run Calories Calculator
Find out how many calories your interval session burns based on your weight and activity type - See calculator
Training Heart Rate Calculator
Check which heart rate zone your intervals should target based on your age and resting pulse - See calculator
VO2max Calculator
Estimate your aerobic ceiling from a Cooper test, Rockport walk or age-based formula - See calculator