Free Fitness Calculators — Calories, Macros, 1RM, BMI & Body Fat
Free, fast fitness calculators that run entirely in your browser — no sign-up, nothing you enter is stored or sent anywhere. Work out your daily calories, macros, one-rep max, BMI, body fat, protein, water intake and ideal weight with the same formulas coaches and researchers actually use.
Our Calculators
TDEE Calculator — Find out exactly how many calories you burn every day, and how many to eat to lose, maintain or gain.
Macro Calculator — Split your calories into protein, carbs and fat for cutting, maintaining or bulking.
One Rep Max Calculator — Estimate your 1RM from any set and get a full percentage table for programming.
BMI Calculator — Check your Body Mass Index and see where you sit on the standard scale.
Body Fat Calculator — Estimate body fat percentage with the US Navy tape-measure method.
BMR Calculator — Work out how many calories your body burns at rest, and what that means at every activity level.
Protein Calculator — Find your daily protein target in grams, matched to your goal — build muscle, lose fat or stay healthy.
Water Intake Calculator — Work out how much water you should drink every day, from your body weight and your training.
Ideal Weight Calculator — See your ideal weight from three established formulas — Devine, Robinson and Miller.
Weight Goal Date Calculator — Find the realistic date you will reach your target weight, at a steady, safe pace.
How to Use This Site
Start with the TDEE Calculator to get your calorie target. Then use the Macro Calculator to turn that target into daily protein, carb and fat goals. Track your strength progress with the One Rep Max Calculator, and check in monthly with the BMI and Body Fat calculators.
Honest, Formula-Based Results
Every calculator on this site shows its formula on the page, with a worked example, so you can check the maths yourself. These are estimates — useful for planning, not medical advice.