CalcNest

Health & Fitness Calculators

Numbers that help you understand your body. Calculate your BMI and see what it does and doesn't mean, estimate the calories you burn each day with the equation dietitians actually use, measure body fat with nothing but a tape measure, or count down to a due date. Each tool explains its formula, its accuracy, and its limits — because health numbers without context mislead.

  • BMI Calculator

    Calculate your BMI instantly in kg/cm or lb/ft-in.

  • Calorie Calculator

    Find your daily calorie needs (TDEE) with the Mifflin-St Jeor equation.

  • BMR Calculator

    Calculate your basal metabolic rate with both the Mifflin-St Jeor and Harris-Benedict equations — the calories your body burns at complete rest.

  • Body Fat Calculator

    Estimate your body fat percentage with just a tape measure using the U.S.

  • Ideal Weight Calculator

    Find your ideal body weight by height and sex using four medical formulas (Devine, Robinson, Miller, Hamwi) plus the healthy BMI range.

  • Pregnancy Due Date Calculator

    Estimate your due date from your last menstrual period, conception date, or IVF transfer.