Body math,
honest numbers.
Free calculators for BMI, calories, body fat, pregnancy, training pace, macros, and more. No subscriptions, no shady supplements — just the formulas.
Try BMI Calculator.
Free, browser-based, no signup. The rest of the category ships in 2026.
35 calculators on the way.
Every major fitness and health calculation covered — from BMI to pregnancy tracking to one-rep max. More sport-specific tools will follow.
Calorie Deficit CalculatorSoon
Calculate daily calorie deficit needed to lose weight at your target rate, with projected timeline.
Water Intake CalculatorSoon
Daily hydration target based on weight, activity level, and climate.
VO2 Max CalculatorSoon
Estimate your VO2 max (aerobic fitness level) from a run test or heart rate data.
Waist-to-Hip Ratio CalculatorSoon
Calculate waist-to-hip ratio and assess cardiovascular health risk category.
Intermittent Fasting CalculatorSoon
Calculate eating and fasting windows for 16:8, 18:6, 5:2, and other IF protocols.
Calorie CalculatorSoon
Daily calorie needs based on age, weight, height, sex, and activity level.
Body Fat CalculatorSoon
Estimate body fat percentage using Navy, Jackson-Pollock, and BMI-based methods.
BMR CalculatorSoon
Basal Metabolic Rate using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas.
Macro CalculatorSoon
Personalized protein, carb, and fat targets based on your goals and TDEE.
Ideal Weight CalculatorSoon
Ideal body weight using Devine, Robinson, Miller, and Hamwi formulas side by side.
Pregnancy CalculatorSoon
Due date, trimester breakdown, and key milestone dates from LMP or conception date.
Pregnancy Weight Gain CalculatorSoon
Recommended total and weekly weight gain by pre-pregnancy BMI and trimester.
Pregnancy Conception CalculatorSoon
Estimate conception date from due date or last menstrual period.
Due Date CalculatorSoon
Estimated due date using Naegele's rule from LMP or known conception date.
Pace CalculatorSoon
Pace, time, and distance — convert between any two. Includes race split planners.
Army Body Fat CalculatorSoon
US Army body fat percentage using neck, waist, and hip circumference measurements.
Carbohydrate CalculatorSoon
Daily carb intake recommendation based on calorie goal, activity, and diet type.
Lean Body Mass CalculatorSoon
Lean mass from total weight and body fat percentage using multiple formulas.
Healthy Weight CalculatorSoon
Healthy weight range for your height using BMI and frame-size adjustments.
Calories Burned CalculatorSoon
Calories burned for 100+ activities based on weight, duration, and MET values.
One Rep Max CalculatorSoon
1RM estimate using Epley, Brzycki, Lander, and 8 other formulas. Compare side-by-side.
Target Heart Rate CalculatorSoon
Max HR and training zones (Z1–Z5) using Karvonen, Tanaka, and HRR formulas.
Protein CalculatorSoon
Daily protein target based on body weight, training intensity, and fitness goal.
Fat Intake CalculatorSoon
Recommended daily fat intake based on calorie goal and dietary fat percentage.
TDEE CalculatorSoon
Total Daily Energy Expenditure across all activity levels with cut/bulk/maintain targets.
Ovulation CalculatorSoon
Estimated ovulation window and fertile days based on cycle length and LMP.
Conception CalculatorSoon
Likely conception date range from a known due date or last menstrual period.
Period CalculatorSoon
Predict future period dates and cycle patterns based on past cycle history.
GFR CalculatorSoon
Estimated Glomerular Filtration Rate (eGFR) from creatinine, age, sex, and race.
Body Type CalculatorSoon
Identify ectomorph, mesomorph, or endomorph body type from measurements.
Body Surface Area CalculatorSoon
BSA using Mosteller, Du Bois, and Haycock formulas — used in medication dosing.
BAC CalculatorSoon
Blood alcohol content estimate based on drinks, weight, sex, and time elapsed.
Anorexic BMI CalculatorSoon
BMI classification with clinical underweight thresholds and health risk context.
Weight Watcher Points CalculatorSoon
Estimate WW PersonalPoints for any food based on calories, fat, sugar, and protein.
Overweight CalculatorSoon
Determine overweight and obesity classification by BMI, waist size, and body fat.
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If you do a specific sport (cycling, swimming, climbing, lifting) and want sport-specific math, tell us your event and we'll prioritize.
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