Health & Fitness Calculators

Calories, BMI, body fat, macros, pregnancy, and fitness calculators built on established medical formulas.

Calorie Calculator

Find your daily calorie needs to maintain, lose, or gain weight.

Calculate your body mass index and see the healthy weight range for your height.

Body Fat Calculator

Estimate your body fat percentage from tape measurements using the U.S. Navy method.

Estimate the calories your body burns at rest and at each activity level.

TDEE Calculator

Find your total daily energy expenditure and maintenance calories.

Macro Calculator

Get daily protein, carb, and fat targets in grams for your goal.

Ideal Weight Calculator

Find your ideal body weight from four medical formulas and the healthy BMI range.

Calories Burned Calculator

Estimate calories burned for 10 common activities using MET values, weight, and duration.

Protein Calculator

Calculate your daily protein target by body weight and training goal, with per-meal amounts.

Pregnancy Due Date Calculator

Estimate your due date, current pregnancy week, and trimester milestones.

Ovulation Calculator

Estimate your ovulation date, fertile window, and next period from your cycle.

Pace Calculator

Solve for running pace, time, or distance, with race projections for 5K to marathon.

Peptide Calculator

Reconstitute a peptide vial and convert your dose to insulin-syringe units.

Convert between A1C and estimated average glucose (eAG), with ADA interpretation bands.

FFMI Calculator

Calculate your fat-free mass index (FFMI) and normalized FFMI to gauge muscularity.

Body Shape Calculator

Determine your body shape from bust, waist, and hip measurements, with your waist-to-hip ratio.

About our health & fitness calculators

Health numbers only help if the formula behind them is legitimate. Every calculator in this section names its method and uses the version supported by research: the Mifflin-St Jeor equation for calories, BMR, and TDEE (the formula the American Dietetic Association found most accurate for healthy adults), the U.S. Navy circumference method for body fat, Naegele’s rule for pregnancy due dates, and the Devine, Robinson, Miller, and Hamwi formulas for ideal weight ranges.

The tools are designed to be used together. Start with BMR to learn what your body burns at rest, TDEE to account for your activity, then the calorie and macro calculators to turn that into daily targets for losing, maintaining, or gaining weight. Runners can pair the pace calculator with the calories-burned tool to plan training around real energy costs. Charts show how your targets ladder from aggressive deficit to surplus, so you can pick a sustainable pace instead of an extreme one.

All results are estimates for healthy adults. They can’t account for medical conditions, medications, or individual metabolism, so treat them as a starting point and confirm anything important with a healthcare professional.