Free tools

Free fitness calculators, no sign-up.

Find your energy expenditure, your macros and your body composition in seconds. Every calculation runs in your browser — nothing is sent to a server.

10 free calculators
Instant result
Runs in your browser

Energy

How much your body burns at rest and across the day.

TDEE Calculator

Estimate daily calorie burn with Mifflin-St Jeor and a 1.2–1.9 activity factor

BMR Calculator

Compare Mifflin-St Jeor and revised Harris-Benedict for resting burn

Nutrition

Calories, macros, protein and hydration for your goal.

Daily calorie calculator

Daily target for fat loss, maintenance or muscle gain, plus time to goal weight

Macro calculator

Daily protein, carbs, and fat in grams from your goal

Protein calculator

Daily protein in g/kg from your goal and training level

Water Intake Calculator

Daily water from 35 ml/kg, 350 ml per 30 min of training, and climate

Body composition

BMI, body fat percentage and healthy weight range.

BMI Calculator

WHO adult BMI bands plus the healthy weight range for your height

Navy Body Fat Calculator

Estimate body fat from neck, waist, and hip with the U.S. Navy formula

Ideal Weight Calculator

Healthy BMI range plus Devine, Robinson, Miller, and Hamwi estimates

Training

Loads and references to program your strength work.

1RM Calculator

Compare Epley, Brzycki and Lombardi plus a load-percentage table

Calculating is the easy part. Sticking to it is not.

FITTA turns these numbers into living targets: every meal, workout or weigh-in updates your progress instantly.

These calculators provide estimates based on population-level formulas and do not replace assessment by a dietitian, physician or exercise professional.