# Guide to the fitness calculators

The fitness calculators deal with running and heart rate. One works out pace, time and distance and predicts race times; the other estimates your maximum heart rate and the training zones that follow from it.

## Fitness

### [Max Heart Rate Calculator](https://www.calculator.land/calculators/max-heart-rate/)

Estimates your maximum heart rate from your age with the Tanaka formula and sets it beside three other formulas (HUNT, Gellish and 220 − age). It divides the result into five training zones on Olympiatoppen's intensity scale, and uses your measured maximum instead if you enter one.

### [Running Pace & Race Time Calculator](https://www.calculator.land/calculators/running-pace/)

Works out your pace, your time or your distance from the other two, in kilometres, miles, metres or yards, and gives your speed alongside. A race predictor estimates times for other distances with Riegel's formula, and an optional body weight and elevation gain add a calorie estimate and an effort pace.

**Quality:**

• - Checked with real keystrokes in the browser in every language version, and passed (October 2026).
• - Calories are estimated at 0.97 kcal per kg of body weight per kilometre run (Mayhew 1977), and elevation gain does not change them: 70 kg and 10 km in 50:00 give 679 kcal both with 0 m and with 1,000 m of climbing.
• - Elevation gain is turned into extra flat distance with Naismith's rule, 7.92 km per 1,000 m of climbing, which gives an effort pace: 70 kg and 10 km in 50:00 with 1,000 m of climbing give 2:47 per km.