Health & Fitness
BMI, calories, body composition, pregnancy, and athletic performance.
38 calculators in this category.
- BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Free BMI calculator for adults in metric and imperial units, with WHO category breakdown.
- BMR / TDEE
Calculate your basal metabolic rate (BMR) and total daily energy expenditure (TDEE) — the calories you burn at rest and with activity.
- Macros
Calculate daily protein, carbohydrate, and fat targets for cutting, maintaining, or bulking. Supports keto, low-carb, and balanced diets.
- Body Fat %
Estimate body fat percentage from neck, waist, and hip measurements using the US Navy circumference formula.
- Ideal Weight
Compute ideal body weight using four classic formulas (Devine, Robinson, Miller, Hamwi) plus a healthy-BMI range.
- Lean Body Mass
Estimate lean body mass (LBM) using the Boer, James, and Hume formulas. Used for medication dosing and body composition tracking.
- Waist-Hip Ratio
Calculate waist-to-hip ratio (WHR), a body shape metric linked to cardiovascular health risk.
- Water Intake
Estimate how much water to drink per day based on your weight, activity level, and climate. Returns liters, ounces, and glasses.
- Heart Rate Zones
Calculate your five training heart rate zones from age and resting heart rate using the Karvonen heart-rate-reserve formula.
- Running Pace
Convert between pace, time, and distance. Predict marathon, half-marathon, 10K, and 5K finish times from a shorter race result.
- One Rep Max
Estimate your one-rep max from a recent set using six common formulas (Epley, Brzycki, Lombardi, Mayhew, O'Conner, Wathen).
- Calorie Deficit
Calculate the calorie deficit needed to lose weight by a target date, and project how long realistic deficits will take.
- Pregnancy Due Date
Estimate your pregnancy due date and how many weeks pregnant you are. Supports last menstrual period (LMP), conception date, and ultrasound dates.
- Ovulation
Estimate ovulation date and fertile window from your last period and cycle length. Useful for trying to conceive or natural cycle tracking.
- Fasting Window
Calculate your eating and fasting windows for 16:8, 18:6, 20:4, OMAD, and custom intermittent fasting protocols.
- Caffeine Half-Life
See how much caffeine remains in your body hours after drinking it, and when it's safe to sleep without disruption.
- BAC
Estimate blood alcohol content based on drinks, body weight, sex, and time. Includes sober-time estimate.
- Sleep Cycle
Calculate optimal bedtime or wake-up time based on 90-minute sleep cycles, with 15-minute fall-asleep buffer.
- Sleep Debt
Track accumulated sleep debt over a week and see how many extra hours you'd need to recover.
- Carbon Footprint
Estimate your annual carbon footprint in tonnes of CO2 from home energy, driving, flights, and diet.
- Dog Age
Convert your dog's age to human years using the modern AVMA-aligned formula — not the outdated 7× myth.
- Cat Age
Convert your cat's age to human years using the modern veterinary aging chart, with milestones for kitten, adult, senior, and geriatric stages.
- Pet Food Cost
Calculate daily, monthly, and yearly pet food cost based on bag size, price, and daily portion.
- Pickleball Score
Track pickleball scores for singles and doubles. Follows official USAPA rules including server number and side-out logic.
- Gaming DPI
Convert mouse sensitivity between FPS games (Valorant, CS2, Apex, Overwatch). Calculate eDPI and equivalent in-game sensitivity.
- TDEE
Estimate total daily calories burned from BMR plus activity level — the starting point for any nutrition plan.
- Protein Intake
Daily protein target in grams based on bodyweight and goal (cut, maintain, bulk).
- W/kg
Calculate FTP power-to-weight ratio and find your cyclist classification (recreational to world-class).
- Swim Pace
Convert total swim time and distance into pace per 100 m or 100 yd, plus split projections.
- Steps Converter
Convert daily step count to distance (km/mi) and approximate calories burned by walking pace.
- FFMI
Calculate Fat-Free Mass Index — a muscle-mass measure that adjusts for height.
- VO2 Max
Estimate aerobic fitness (VO2 max) from age and resting heart rate.
- BP Classifier
Classify your blood pressure reading per the 2017 ACC/AHA guidelines.
- Cholesterol Ratio
Calculate Total/HDL and LDL/HDL cholesterol ratios — stronger CVD predictors than totals.
- Chronotype
Find your chronotype and optimal bedtime/wake time based on natural sleep midpoint.
- Cycle Tracker
Predict next 3 periods, fertile window, and ovulation from last period and cycle length.
- Glucose Units
Convert blood glucose between US (mg/dL) and international (mmol/L) units, with category.
- METs Calories
Calculate calories burned for any activity using its MET value and your bodyweight.