Free calculators
Fast, accurate fitness math — free, no sign-up.
Calories, macros, BMI, one-rep max and more. Get your answer in seconds, then let Flun keep the numbers up to date for you.
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Calorie Calculator
How many calories to eat for your weight-loss or weight-gain goal.Maintenance Calories
The daily calories that keep your weight exactly where it is.Macro Calculator
Turn your calorie target into protein, carb and fat gram goals.BMR Calculator
Your basal metabolic rate and daily maintenance calories.BMI Calculator
Your Body Mass Index and where it falls on the WHO scale.More calculators
Bulking Calculator
Calories and macros for a controlled muscle-building surplus.Intermittent Fasting
Split your weekly calories across 5:2 and 4:3 fasting schedules.Zig Zag Calculator
Cycle calories high and low across the week at the same weekly total.Adaptive TDEE
Learn your true maintenance calories from your own intake and weight.Body Fat Percentage
Estimate body fat and lean mass — US Navy tape or BMI method.Ideal Bodyweight
The healthy weight range for your height, and a target to aim for.Max Bench (1RM)
Estimate your one-rep max and a working-set percentage table.