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Health & Fitness

BMI, calorie, heart rate and workout calculators

15 tools available

About Health & Fitness

From BMI and body fat to calories, macros, hydration and heart-rate zones, these calculators help you understand and plan your health and fitness goals with instant, actionable results.

Everything runs locally in your browser and is free to use. Treat results as a general guide alongside advice from a qualified professional.

Frequently Asked Questions

How accurate are BMI and body-fat estimates?

They apply validated formulas (WHO BMI ranges, US Navy circumference method) to your inputs - useful screening guides rather than clinical measurements. Athletic builds can skew BMI, for example.

Do you keep my health data?

Never. Calculations run in your browser and inputs vanish when you leave the page - no accounts, no tracking of personal metrics.

Which formula does the calorie calculator use?

Mifflin-St Jeor for basal metabolic rate, multiplied by activity factors for TDEE targets - the approach most dietitians consider a reliable starting estimate.

Can I use these during pregnancy?

The due-date calculator follows Naegele's rule for estimation. For nutrition targets during pregnancy, use results as conversation starters with your doctor rather than prescriptions.

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