17 tools · Five ways to explore
Health & Fitness Calculators
Understand the numbers behind daily energy, nutrition, body measurements and training. Start with a question, explore an estimate and learn what it can—and cannot—tell you.
Explore the toolsPopular starting points
A selection for common questions—not a usage ranking.
BMI Calculator
Calculate BMI from height and weight, with adult screening categories and their limitations.
Open calculatorTDEE / Daily Calorie Calculator
Estimate daily maintenance calories from resting energy and an activity multiplier.
Open calculatorMacro Calculator
Convert a calorie budget into protein, carbohydrate and fat grams using your selected proportions.
Open calculatorOne Rep Max Calculator
Estimate a one-repetition maximum from a completed set and view illustrative training percentages.
Open calculatorChoose your goal
Lose weight
Build muscle
Plan nutrition
Understand body composition
Explore training
All Health & Fitness calculators
Weight management
TDEE / Daily Calorie Calculator
Estimate daily maintenance calories from resting energy and an activity multiplier.
Open calculatorCalorie Deficit Calculator
Explore a modest calorie reduction from maintenance, with clear limits and no promised weight loss.
Open calculatorCalorie Surplus Calculator
Compare a small energy surplus with maintenance calories for an illustrative muscle-gain scenario.
Open calculatorWeight Loss Timeline Calculator
Explore a simplified energy-equivalent timescale with safeguards and nonlinear-progress caveats.
Open calculatorNutrition
Macro Calculator
Convert a calorie budget into protein, carbohydrate and fat grams using your selected proportions.
Open calculatorProtein Intake Calculator
Compare an adult protein reference with a sports-nutrition range based on body weight.
Open calculatorWater Intake Calculator
Explore total-water reference values and how an assumed contribution from food changes beverage volume.
Open calculatorBody composition
BMI Calculator
Calculate BMI from height and weight, with adult screening categories and their limitations.
Open calculatorIdeal Weight Calculator
Find the weight interval corresponding to an adult BMI reference range—not a personal ideal.
Open calculatorBody Fat Calculator
Explore a BMI-based Deurenberg body-fat estimate and understand why it is not a measurement.
Open calculatorLean Body Mass Calculator
Separate estimated fat and fat-free mass using body weight and an existing body-fat percentage.
Open calculatorTraining
One Rep Max Calculator
Estimate a one-repetition maximum from a completed set and view illustrative training percentages.
Open calculatorPace Calculator
Calculate running or walking pace and speed in kilometres and miles from distance and time.
Open calculatorCalories Burned Calculator
Estimate gross and above-rest activity energy using MET values, weight and duration.
Open calculatorSteps to Calories Calculator
Turn measured walking steps, step length and duration into a rough level-walking energy estimate.
Open calculatorGeneral fitness references
Learn before you compare
Our focused guides explain BMI and resting energy in depth. The related articles separate body-size screening from energy estimates, explain how body-fat estimates are produced, and show how to interpret a moderate calorie-deficit scenario without treating it as a prescription.
Frequently asked questions
Where should I start with calories?
Start with daily maintenance calories. Then use the deficit, surplus or macro tool to explore one explicitly stated assumption at a time.
Are these tools for medical decisions?
No. They are educational adult estimators, not diagnostic tools or personalized clinical advice.
Are my body measurements saved?
The English Health & Fitness forms calculate in the current browser tab without saving your inputs to calculation history or sending them to a calculation service.
Can I switch between metric and imperial?
Yes. Relevant forms support kg/lb, cm or feet and inches, and kilometres/miles. Labels show the units being used.