Fitness Calculators
Calculate calories burned, cycling calories and distance to steps and other fitness calculations.
Training tools for runners, walkers and lifters: pace and race planning, heart-rate zones, strength estimates and the calories an activity burns. Each uses a named, published formula, and each is an estimate you can check against how a session actually feels.
Which Fitness calculator do you need?
- What pace am I running, or what pace do I need?Pace CalculatorPace and speed from any distance and time.
- What could I run at a longer or shorter distance?Race Time PredictorPredicts a race time from a recent result using Riegel's formula.
- What paces should my training runs be?Training Pace CalculatorEasy, long-run, tempo and interval paces derived from your race pace.
- What heart rate should I train at?Target Heart Rate CalculatorKarvonen method, which uses your resting heart rate as well as your age.
- How much can I lift for one rep?One Rep Max CalculatorEstimates a one-rep max from the weight and reps of a set, using the Epley and Brzycki formulas.
- How many calories did an activity burn?Calories Burned CalculatorMET-based estimate from activity, bodyweight and duration.
All Fitness Calculators
Zones from age alone vs from resting heart rate
The heart rate zone calculator takes percentages of an age-predicted maximum. The target heart rate calculator also uses your resting heart rate (the Karvonen method), so two people of the same age but different fitness get different zones — usually the more useful answer if you know your resting rate.
Limitations
- Age-predicted maximum heart rate can be off by a wide margin for an individual.
- Calorie and 1RM figures are estimates; stop and seek advice if exercise causes pain or dizziness.
Fitness Guides
Heart Rate Training Zones Explained: The Five-Zone Model
The standard five-zone training model divides your estimated maximum heart rate (220 minus age) into five bands from 50% to 100%, each corresponding to a different training intensity and physiological effect — from easy recovery pace at the low end to maximum, unsustainable effort at the top.
Read guideHow a Step Count Converts Into Distance Walked
Converting steps into distance is a single multiplication by stride length — the same step count covers more ground for someone with a longer stride, which is why there's no single universal steps-to-distance ratio.
Read guideHow Calories Burned During Exercise Are Calculated
Calories burned come from a MET value — how many times more energy an activity uses compared to resting — multiplied by bodyweight and a standard constant, then scaled by how long the activity lasts.
Read guideHow Calories Burned From a Step Count Are Calculated
Calories burned from steps use a simple per-step, per-kilogram rate — a heavier person burns more from the identical step count, since moving more body mass takes more energy per step.
Read guideHow One Rep Max Is Estimated With Epley and Brzycki
Two different formulas estimate the same one-rep max from a sub-maximal lift, usually disagreeing slightly — except at exactly 10 reps, where they converge.
Read guide