Endurometry
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
Training plan generator
Build a 4–16 week running plan from your recent race and weekly volume. Free: 2 plans/month. Pro: higher limits + CSV export.
Printable Pace Wristband
Generate a single-column pace wristband sized to your wrist — no cutting, just wrap it once. Pick even / negative / positive split and 1/2/5/10 km (or mi) intervals, then print at 100%.
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.
KPH to MPH Converter (km/h to mph)
Convert kph to mph instantly: mph = km/h × 0.621371, so 100 km/h = 62.14 mph. Free km/h to miles per hour chart for road and running speeds, plus mph to km/h.
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 a finish time to an approximate open-class (20–29) equivalent using Endurometry age factors — not official WMA tables.
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 a flat outdoor pace of the same ACSM oxygen cost, or the belt setting that matches an outdoor pace.
Race Cutoff Time Calculator
Compare a planned even pace plus start-line delay with the course time limit, and see a linear checkpoint sketch — not the official race table.
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 Chart Generator
Enter a goal finish time and get a pace chart in both min/km and min/mile, a speed-to-pace conversion table, your tempo pace and a printable wristband.
Want a structured training plan?
Free calculators stay free. Pro adds more training plans, printable wristbands, saved history and CSV export for $7/month.
Pace Charts
See the split time for every kilometre at your goal finish time: Pace Charts
Guides
How to put the numbers to work:
What Is Running Pace? · Pace vs Speed · min/km ↔ min/mile · How to Calculate Race Splits · Marathon Pace Strategy · Race time prediction explained · Estimate a marathon finish time · 5K, 10K and half marathon pace · Race Day Checklist · Heart Rate Zones Explained · Pace vs heart rate training · Training Paces Explained · VDOT explained · Easy, Tempo and Long Run Paces · Treadmill vs outdoor pace · Negative vs positive split · How to use a pace band · How race cutoffs work · General Physical Preparation for Runners (GPP)
Garmin metrics & battery life
What your watch is actually telling you: Garmin metrics explained
Garmin Body Battery explained · Garmin HRV status explained · Garmin sleep score explained · Garmin stress score explained · Garmin recovery time explained
Garmin Forerunner 265 battery life · Garmin Forerunner 965 battery life · Garmin fēnix 8 battery life · Garmin Venu 3 battery life
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?
Not for the free calculators — they run in your browser. An optional account unlocks Pro training plans and export.
Can I use this for a coaching plan?
You may cite the results, but please combine them with professional coaching judgement.
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.
KPH to MPH Converter (km/h to mph)
Convert kph to mph instantly: mph = km/h × 0.621371, so 100 km/h = 62.14 mph. Free km/h to miles per hour chart for road and running speeds, plus mph to km/h.
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 a finish time to an approximate open-class (20–29) equivalent using Endurometry age factors — not official WMA tables.
Want a new tool or fix?
Tell us which calculator, pace chart or fix would help — we build what runners ask for. Replies usually come back in 1–2 days.