Free Fitness Calculators for Calories, Protein and Macros

Simple, science-based calculators to help you hit your nutrition targets —
whether you want to lose fat, build muscle, or maintain your weight.
No account needed. No fluff. Just your numbers.

✓ Free forever ✓ No account needed ✓ 7 calculators ✓ Science-based formulas

Why CalcFitness?

  • Free forever — no account, no paywall, no subscription
  • Science-based formulas — we use established equations like
    Mifflin-St Jeor, not guesswork
  • Metric and imperial — switch between kg/lb and cm/ft instantly
  • No bloat — fast, clean, mobile-friendly calculators that
    just work
  • Built for real goals — fat loss, maintenance, and muscle
    gain covered across every calculator

Our Calculators

TDEE Calculator
Find your total daily calorie needs based on your stats and activity level.
Open calculator
BMR Calculator
Calculate the calories your body burns at complete rest.
Open calculator
Protein Calculator
Find your ideal daily protein intake based on your weight and goal.
Open calculator
Macro Calculator
Break your calories into protein, carbs, and fat for your specific goal.
Open calculator
BMI Calculator
Calculate your Body Mass Index and find out what it means for your health.
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Calorie Deficit Calculator
Set your daily calorie target and timeline to reach your goal weight.
Open calculator
Body Fat % Calculator
Estimate your body fat percentage using the US Navy method.
Open calculator

How it works

1. Pick your calculator

Start with the TDEE Calculator to find your daily
calorie needs — it’s the foundation everything else builds on.

2. Enter your stats

Input your age, weight, height, activity level,
and goal. Your data stays in your browser — we don’t store anything.

3. Get your numbers

Instantly see your personalized calorie and macro
targets. Use them as your starting point and adjust based on real results
over 2–3 weeks.

Last updated: April 2026