21 free tools

All Calculators

Science-backed health and nutrition calculators. Pick a tool, get your numbers.

Nutrition

Macro Calculator

Calculate your optimal protein, carbs, and fat targets based on your TDEE and goal.

Nutrition

TDEE Calculator

Find your Total Daily Energy Expenditure — the calories your body burns across the entire day.

Nutrition

Calorie Deficit Calculator

Set your daily calorie deficit and get an estimated timeline to reach your goal weight.

Nutrition

Protein Calculator

Get your daily protein target based on your bodyweight, goal, and activity level.

Body

BMI Calculator

Calculate your Body Mass Index with category classification and a visual gauge.

Body

BMR Calculator

Calculate your Basal Metabolic Rate — calories your body burns at complete rest.

Body

Body Fat Calculator

Estimate your body fat percentage with the US Navy tape-measure method. No equipment needed.

Body

Ideal Weight Calculator

Find your healthy goal weight range using four science-backed formulas by height and sex.

Body

Lean Body Mass Calculator

Calculate your LBM and get a precise Katch-McArdle BMR. Two methods: with or without body fat %.

Activity

Calorie Burn Calculator

Calculate calories burned for 30+ exercises using MET values from Ainsworth et al. 2011.

Activity

Water Intake Calculator

Get a personalized hydration target based on weight, activity, climate, and exercise.

Activity

One Rep Max Calculator

Estimate your 1RM for any lift using 6 validated formulas. Get full training zone breakdown.

Activity

Heart Rate Zone Calculator

Calculate your 5 training zones using the Karvonen formula. Optimize fat burn and VO₂ max.

Activity

Steps to Calorie Calculator

Convert your daily step count to calories burned. Find out how many steps equal 500 calories.

Body

Waist-to-Hip Ratio Calculator

Calculate your WHR and assess body shape and cardiovascular health risk using WHO standards.

Nutrition

Fiber Intake Calculator

Get your personalized daily fiber target with soluble/insoluble split and top food sources.

Nutrition

Vitamin D Calculator

Calculate your recommended vitamin D intake based on age, sun exposure, and skin tone.

Wellness

Sleep Calculator

Find the best bedtime or wake-up time based on 90-minute sleep cycles. Wake refreshed.

Wellness

Age Calculator

Calculate your exact age in years, months, days, and hours. Find days until your birthday.

Wellness

Pregnancy Weight Gain Calculator

IOM 2009 recommended weight gain by pre-pregnancy BMI with trimester-by-trimester targets.

Wellness

BAC Calculator

Estimate blood alcohol content using the Widmark formula. Calculate time to reach zero BAC.

21Calculators
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ScienceBacked formulas