Know Your Numbers.
Trust the Science.
Free, science-backed calculators for fitness, nutrition, pregnancy, and sleep. Validated against WHO, CDC, and ACSM standards, and they run entirely in your browser.
- Clinically validated formulas
- Nothing stored or tracked
- Works on any device
Featured calculators
A handful of the tools people reach for most. Browse the full library for all 75.
BMI Calculator
See where you sit on the WHO scale and your healthy weight range.
Open tool NutritionTDEE Calculator
Find the calories you burn each day, with fat-loss and gain targets.
Open tool Body CompositionBody Fat Calculator
Estimate your body fat percentage with the US Navy method.
Open tool NutritionMacro Calculator
Split your calories into protein, carbs, and fat for your goal.
Open tool NutritionCalorie Calculator
Turn a goal weight and timeframe into a daily calorie target.
Open tool SleepSleep Calculator
Wake up between 90-minute cycles and feel refreshed.
Open toolFind the right tool fast
Six focused categories cover body, food, training, pregnancy, sleep, and clinical estimates.
Body Composition
13 toolsBMI, body fat, lean mass, waist ratio, and more.
View toolsNutrition
11 toolsCalories, macros, protein, water, and fiber targets.
View toolsFitness
15 toolsHeart rate zones, one-rep max, pace, and VO2 max.
View toolsPregnancy
12 toolsDue date, ovulation, conception, and weight gain.
View toolsSleep
3 toolsCycle timing, sleep debt, and sleep quality scores.
View toolsMedical
12 toolsBlood alcohol estimate and kidney function (eGFR).
View toolsPets Fitness
9 toolsDog and cat age, weight, pregnancy, and gestation tools.
View toolsThree steps to your answer
Pick a calculator
Choose from 75 tools across seven health categories.
Enter your numbers
Type a few details. Everything stays on your device.
Get clear results
See science-backed numbers with plain-language guidance.
Accurate, private, and free
No accounts, no paywalls, no data harvesting. Just tools that respect your time and your privacy.
Science-backed
Every formula comes from peer-reviewed research and clinical guidelines, listed on each tool page.
Private by design
All math runs in your browser. Your numbers are never sent, stored, or sold.
Instant results
No loading, no waiting. Type your details and your answer appears at once.
Works anywhere
Phone, tablet, or desktop. The tools adapt to any screen, with nothing to install.
Guides worth reading
Plain-language articles that turn health science into action.
How To Calculate Macros For Fat Loss?
Calories first, then protein, carbs, and fat for steady fat loss.
Read article BodyHow To Calculate Your Body Fat Percentage?
Use the US Navy tape method, learn healthy ranges, and lower it.
Read article PregnancyHow To Calculate Pregnancy Week By Week?
Count from your last period and follow each trimester.
Read articleReady to take control of your health?
Browse the full library of 75 free calculators. No sign-up needed.
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