BMI Calculator
Free adult BMI calculator. Enter height and weight in metric or imperial units to see your BMI score and WHO-style category — plus context on what BMI does and does not mean.
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Free fitness & health calculators
Instant BMI, BMR, TDEE, macros, calories burned, water intake, one-rep max, heart-rate zones, body fat, ideal weight, and running pace — each with a clear guide and FAQ so you know what the number means. Estimates only; not medical advice.
All Habbeat calculators
BMR & TDEE Calculator
Free BMR and TDEE calculator using the Mifflin–St Jeor equation. Estimate basal metabolic rate and total daily energy expenditure from age, sex, height, weight, and activity level.
Open free calculatorMacro & Nutrient Calculator
Free macro calculator for protein, carbohydrates, and fat based on your estimated TDEE, plus fiber targets and typical adult micronutrient reference amounts.
Open free calculatorCalories Burned Calculator
Free calories burned calculator using MET values and your body weight. Estimate energy cost for walking, running, cycling, swimming, weights, HIIT, and other common activities.
Open free calculatorWater Intake Calculator
Free daily water intake calculator. Get a starting fluid target from body weight (~35 ml per kg), shown in millilitres and US cups — then adjust for heat and training.
Open free calculatorOne-Rep Max (1RM) Calculator
Free one-rep max calculator using the Epley formula. Enter the weight you lifted and reps completed (1–15) to estimate your 1RM for programming percentages.
Open free calculatorHeart Rate Zone Calculator
Free heart rate zone calculator. Estimate max heart rate with the Tanaka formula and see Zone 1–5 training ranges for recovery, easy runs, tempo, threshold, and max effort.
Open free calculatorBody Fat Calculator
Free body fat percentage calculator using the US Navy circumference method. Enter height, neck, waist (and hips for women) for an educational estimate — not a lab measurement.
Open free calculatorIdeal Weight Calculator
Free ideal body weight calculator. See the Devine formula estimate for your height and sex, plus the adult BMI 18.5–24.9 healthy weight range for context.
Open free calculatorRunning Pace Calculator
Free running pace calculator. Enter distance and finish time to get min/km (and min/mile), or project 5K, 10K, half, and marathon finish times from your pace.
Open free calculatorWhy use Habbeat calculators?
Most people open a calculator when they want a fast answer — then leave unsure what to do next. Habbeat tools show the estimate up front, then explain the formula, worked examples, limitations, and FAQs in plain language.
When you are ready to turn numbers into habits, continue in the Habbeat app for daily score, food logging, and movement — or build a diet plan on the web.
Tools FAQ
Are Habbeat fitness calculators free?
Yes. Every tool on this page — BMI, BMR/TDEE, macros, calories burned, water, 1RM, heart-rate zones, body fat, ideal weight, and running pace — is free to use in your browser.
Are these calculators medical advice?
No. Results are educational estimates only. For diagnosis, medication, pregnancy, or clinical nutrition, speak with a qualified professional.
Which calculator should I use first?
Start with BMI for a quick height–weight screen, BMR & TDEE for calorie planning, then macros if you want protein/carb/fat targets. Athletes often add 1RM or heart-rate zones next.
Disclaimer: These tools provide general estimates only. They are not medical advice. For health conditions, pregnancy, or personalised nutrition, speak with a qualified professional.