Crush your fitness goals with real numbers.
Track Your Fitness Goals with Science-Based Calculators. Free calculators for calories, macros, body composition and performance — instant results.
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Free tools across the things that actually move the needle.
Body Composition
Energy & Nutrition
Basal Metabolic Rate via Mifflin-St Jeor and Harris-Benedict.
Calculate now →Daily calorie target for loss, maintenance or gain.
Calculate now →Protein, fat and carb split for your diet style.
Calculate now →Total Daily Energy Expenditure by activity level.
Calculate now →Latest guides
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A practical, science-based look at new Research on Optimal Protein Intake — what it means, how to do it, and how to apply it to your own goals.
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A practical, science-based look at 2026 Fitness Trends Backed by Science — what it means, how to do it, and how to apply it to your own goals.
Treadmill vs Outdoor Running: Calorie Burn
A practical, science-based look at treadmill vs Outdoor Running: Calorie Burn — what it means, how to do it, and how to apply it to your own goals.
Real science. Zero fluff.
Every calculator uses established formulas — Mifflin-St Jeor, the US Navy body fat method, Epley and more — with the math shown so you always know where your number comes from.
About SmartFitCalcsHealth and fitness calculations are estimates only and not medical advice. Consult a healthcare provider before changing your diet or exercise routine.