Free Health & Fitness Calculators

BMI Calculator — Body Mass Index & Healthy Weight

Calculate your BMI instantly with metric or imperial units. See your weight category, BMI Prime, Ponderal Index, healthy weight range, and personalised recommendations using WHO standards.

Calorie Calculator — TDEE & Weight Goals

Calculate daily calories using Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle. Find your TDEE and set calorie targets for weight loss, maintenance, or muscle gain.

Body Fat Percentage Calculator — US Navy Method

Estimate body fat percentage using the US Navy circumference method. See lean mass, fat mass, body composition category, and a BMI-based comparison — in metric or imperial units.

Heart Rate Zone Calculator — 5 Training Zones

Calculate all 5 heart rate training zones using Max HR % or Karvonen method. Supports Standard, Tanaka, and Gellish formulas with visual zone bar chart.

Ideal Weight Calculator

Calculate ideal body weight using Devine, Robinson, Miller, and Hamwi formulas.

Water Intake Calculator — Hydration

Calculate your recommended daily water intake based on weight, activity level, and climate.

Running Pace Calculator

Calculate pace, speed, distance, or time for running, walking, and cycling activities.

Macronutrient Calculator — Macros

Calculate your daily protein, carbohydrate, and fat targets based on your TDEE and goals.

BMR Calculator — Basal Metabolic Rate & TDEE

Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Compare all three formulas and see daily calorie targets by goal.

Sleep Calculator — Best Bedtime

Calculate ideal bedtimes or wake-up times based on 90-minute sleep cycles. Find out when to sleep or wake to feel refreshed and avoid mid-cycle grogginess.

TDEE Calculator — Total Daily Energy Expenditure

Calculate your Total Daily Energy Expenditure (TDEE) with macro targets using the Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Set weight goals and see calorie targets for loss, maintenance, and gain.

Pregnancy Due Date Calculator — EDD & Milestones

Calculate your estimated due date from LMP, conception date, IVF transfer date, or ultrasound. Get week-by-week milestones, trimester dates, and key prenatal appointment windows.

Ovulation Calculator — Fertile Window & Cycle Tracking

Predict your fertile window and ovulation date from your cycle length and last period. Includes a 6-cycle fertility calendar, basal body temperature interpretation, and the LH surge timeline.

One-Rep Max Calculator — 1RM & Training Loads

Calculate your one-rep max using Epley, Brzycki, Lombardi, and O'Conner formulas. Get full training load percentages for 50–95% of 1RM and compare formulas to find your most accurate estimate.

Waist-to-Hip Ratio Calculator — WHR & Health Risk

Calculate your waist-to-hip ratio and see your WHO cardiovascular risk category. Includes waist-to-height ratio, a body shape comparison (apple vs. pear), and healthy range targets by sex and age.

VO2 Max Calculator — Fitness Level & Training Zones

Estimate VO2 max from a 1.5-mile run, Rockport walk test, resting heart rate, or submaximal cycle test. Get your fitness percentile, aerobic age, and five heart-rate training zones.

Caloric Deficit Calculator — Lose Weight Safely

Calculate the daily calorie deficit you need to reach your goal weight by a target date. Based on TDEE and BMR. Shows safe deficit ranges, recommended macro splits, estimated weekly loss, and how long to reach your goal at different deficit levels.

Calories Burned Calculator — 40+ Activities & MET

Calculate calories burned during any exercise or physical activity using MET values, body weight, and duration. Covers 40+ activities including running, cycling, swimming, weightlifting, and daily tasks. Compares net vs gross calories burned.

Lean Body Mass Calculator — LBM & Fat-Free Mass

Calculate lean body mass (LBM) using four clinical formulas: Boer, James, Hume, and Peters. Get fat mass, fat-free mass, skeletal muscle mass estimate, and ideal protein intake based on LBM. Used in medicine for drug dosing and fitness for muscle tracking.