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.
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Protein Calculator
Find your ideal daily protein intake based on your weight and goal.
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Macro Calculator
Break your calories into protein, carbs, and fat for your specific goal.
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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.
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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.