28 free health calculators

Know your numbers.
Take control of your health.

Fast, accurate calculators for body metrics, nutrition, fitness, heart health, and pregnancy. All math runs in your browser — no sign-up, no tracking.

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🧮 Body Metrics & Weight

Body Mass Index — check if your weight is healthy for your height.

Body Fat % Calculator

Estimate body fat using the US Navy circumference method.

Lean Body Mass Calculator

How much of your weight is lean tissue vs fat.

Ideal Body Weight Calculator

Devine formula for ideal weight by height.

Reverse BMI Calculator

Target weight from your height and goal BMI.

Healthy Weight Range

Full weight range for each BMI category at your height.

Waist-to-Height Ratio

Simpler health risk indicator than BMI.

Body Surface Area using 5 medical formulas.

🥗 Energy & Nutrition

Mifflin-St Jeor formula for calories burned at rest.

TDEE Calculator

Total Daily Energy Expenditure = BMR x activity.

Calorie Calculator

Daily calorie needs based on BMR + activity level.

Calorie Deficit Calculator

Weekly fat loss from your deficit — sustainable or aggressive?

Macro Calculator

Protein, carbs, and fat targets for your goal.

Water Intake Calculator

Daily hydration needs from weight + activity.

kJ ↔ Calories Converter

Convert kilojoules to Calories for any nutrition label.

❤️ Heart & Blood

Mean Arterial Pressure and Pulse Pressure from systolic/diastolic.

Blood Sugar Converter

Convert mg/dL to mmol/L and vice versa.

🏃 Fitness & Exercise

Heart Rate Zones

Karvonen method — 5 training zones from resting HR.

Target Heart Rate

Simple % of max HR for fat burn, cardio, peak training.

Pace Calculator

Convert min/mile ↔ min/km ↔ mph ↔ km/h instantly.

Calories Burned by Distance

Walk/run/cycle distance → calories — no pace needed.

MET to Calories

Estimate calories burned for any activity by MET value.

One Rep Max (1RM)

Estimate your max lift from any weight x reps.

Race Time Predictor

Predict 5K/10K/half/marathon from any race result.

VO2 Max Calculator

Cardiovascular fitness from resting HR, Cooper, or Rockport.

👶 Pregnancy

Due Date Calculator

Estimated delivery date from LMP.

Ovulation Calculator

Fertile window and ovulation date from cycle length.

😴 Sleep

Sleep Calculator

Best sleep/wake times based on 90-minute cycles.

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