A set of free online tools for runners: pace calculation, race time prediction, training pace zones, printable pace bands, cutoff checks and more. Everything runs locally in your browser — no sign-up, no uploads.
Built on published sports-science models: the Riegel power law, Daniels–Gilbert VO2max, ACSM metabolic equations and Karvonen heart-rate reserve.
All Tools
Running Pace Calculator
Enter distance and finish time to get your pace per km and mile, average speed and per-kilometre splits.
Running Pace Converter
Convert between min/km, min/mi, km/h and mph, and see the implied finish time for 5K, 10K, half marathon and marathon.
Race Time Predictor
Predict your finish time at any distance using the Riegel power law and the Daniels–Gilbert VO2max model.
Training Pace Calculator (VDOT Zones)
Get your VDOT from a recent race and see easy, marathon, threshold, interval and repetition pace zones plus heart-rate zones.
Age Grading Calculator
Convert your result into an open-class equivalent time using WMA age factors, and compare across ages.
Heart Rate Zone Calculator
Calculate your five running heart-rate zones from age, resting heart rate and max heart rate using the Karvonen method.
Pace Band Generator
Generate a printable pace band with the time you should pass every kilometre or mile at your goal finish time.
Treadmill Pace Calculator
Convert treadmill speed and incline to an equivalent outdoor pace, or find the setting for your outdoor target pace.
Race Cutoff Time Calculator
Check whether your planned pace beats the course cutoff, with key checkpoint times and your safety buffer.
Weight vs Pace Calculator
Estimate how a change in body weight affects your race time and your seconds per kilometre.
Running Calorie Calculator
Estimate calories burned running from your weight, pace, duration and grade using the ACSM metabolic equation.
Average Running Finish Times
Average 5K, 10K, half marathon and marathon times by age and gender, plus submit your own result anonymously.
Pace Charts
See the split time for every kilometre at your goal finish time: Pace Charts
Frequently Asked Questions
Are these calculations accurate?
They use published sports-science models and are estimates. Real results depend on training, weather, course and fuelling.
Do I need to sign up?
No. Everything runs locally in your browser and nothing is uploaded.
Can I use this for a coaching plan?
You may cite the results, but please combine them with professional coaching judgement.
Gear runners ask about
GPS running watch
Pace, laps and alerts on your wrist
Chest strap heart-rate monitor
More reliable than wrist-based HR
Race day running shoes
Lightweight shoes for tempo and race pace
Some links on this page are affiliate links. If you buy through them we may earn a commission at no extra cost to you.
Related Tools
Running Pace Calculator
Enter distance and finish time to get your pace per km and mile, average speed and per-kilometre splits.
Running Pace Converter
Convert between min/km, min/mi, km/h and mph, and see the implied finish time for 5K, 10K, half marathon and marathon.
Race Time Predictor
Predict your finish time at any distance using the Riegel power law and the Daniels–Gilbert VO2max model.
Training Pace Calculator (VDOT Zones)
Get your VDOT from a recent race and see easy, marathon, threshold, interval and repetition pace zones plus heart-rate zones.
Age Grading Calculator
Convert your result into an open-class equivalent time using WMA age factors, and compare across ages.
Heart Rate Zone Calculator
Calculate your five running heart-rate zones from age, resting heart rate and max heart rate using the Karvonen method.
Get new tools by email
Occasional emails when we ship a new calculator or pace chart. No spam, unsubscribe anytime.