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Running calculators for training, racing, and fitness

Pace, calories, race predictions, splits, VO2 max, and heart-rate zones. Every result shows its formula, sources, and limits.

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Documented methodologyMiles and kilometersShareable results

Runner's GPS watch showing distance, time, and pace

GPS watch, mid-split

Pace

4:52/km

Calories

612kcal

HR zones · Zone 2

108-126bpm

Splits · 10K

5:00avg/km

Featured calculators

Start with the four runners reach for most

All 6 calculators

Running Calorie Calculator

Calories from weight, distance, pace, and elevation.

Running Pace Calculator

Pace, speed, min/mile and min/km from distance and time.

Heart Rate Zone Calculator

Five training zones from age or known max heart rate.

VO2 Max Calculator

Aerobic fitness from a 12-minute Cooper run test.

Start with a question

What are you trying to figure out?

Most runners arrive with one specific question. Pick yours and go straight to the right tool.

How many calories did my run burn?Factor in weight, distance, pace, and elevation.Calorie Calculator What pace do I need to hit my goal?Convert distance and time to min/mile and min/km.Pace Calculator What could I run for my next race?Predict a finish time from a recent result.Race Predictor What heart-rate zone is easy?Find your Zone 2 range from age or known max HR.Heart Rate Zones How fit am I aerobically?Estimate VO2 max from a 12-minute Cooper run.VO2 Max Calculator

Field guides

Understand the numbers behind the tools

Short, plain-language explainers with formulas, examples, and limits.

View all guides

Diverse group of runners on a path with green energy trail accents

Calories · Guide

Calories Burned Running by Distance

How distance, pace, weight, and elevation change the estimate.

Two runners checking pace and speed on a running path

Pace vs Speed for Runners

When to use each metric, and how to convert between them.

Diverse running group jogging comfortably on a shaded trail

Heart rate · Guide

Zone 2 Running Heart Rate

What Zone 2 means and why easy pace varies by runner.

Diverse runners doing a track workout for aerobic fitness

VO2 Max · Guide

VO2 Max for Runners

What field estimates measure, and what they do not.

Methodology and sources

Planning numbers, not black-box outputs

Every calculator documents its formula, the assumptions behind it, and where it falls short. Pace and split math is exact arithmetic; physiology estimates use published field formulas and say so.

Read the methodology

Exact arithmetic

Pace, speed, distance conversion, and splits are deterministic.

Named sources

2024 Compendium MET values, the Riegel formula, and the Cooper 12-minute test.

Stated limits

Field estimates are not lab measurements, and each tool says where it is weak.