24 free tools

Fitness calculators

Every AltF fitness calculator in one place. Start with the four-step plan builder, then dig into body composition, energy, training and steps.

The four-step plan builder

One profile, four connected tools: change your weight in step 1 and the meals in step 4 follow.

Step 01 · MeasureBMI calculatorSee your BMI, what it means, and a healthy weight for your height — plus how far you are from it.Check my BMI
Step 02 · FuelCalorie calculatorFind out how many calories to eat each day for your goal, and how much protein, fat and carbs that means.Work out my calories
Step 03 · TrainWorkout generatorGet a week of workouts made for your goal, your experience, your free time and the equipment you have.Build my workout
Step 04 · EatMeal plannerGet seven days of meals that match your calories, for the way you eat — with measured portions and a shopping list.Plan my meals

Body & weight

Size, shape and composition: useful snapshots, best read as trends over time.

Energy & nutrition

How much energy you use, and how to split what you eat.

Training & cardio

Plan loads, zones and intervals for strength and cardio sessions.

Steps & walking

Walking is the easiest way to add activity minutes to your week.

Put the numbers to work

Pick a ready-made workout plan

Eight free weekly routines, from a 20-minute workout to push pull legs.

See the plans Track progress

Questions people ask

Which fitness calculator should I start with?

Start with the BMI calculator for a quick picture of where you are, then the calorie calculator for daily calories and macros. The workout generator and meal planner use those same numbers.

How accurate are these calculators?

They use published formulas (for example Mifflin-St Jeor for resting energy), which give good estimates for most adults but cannot measure you directly. Treat the results as a starting point and adjust based on how your weight and energy change over a few weeks.

Do the calculators save my data?

The four AltF Fitness tools keep your answers on this device only, so you don't have to re-enter them. Nothing is uploaded or shared.

Are BMI and body fat results a diagnosis?

No. They are screening estimates. BMI doesn't tell muscle from fat, so talk to a doctor if a result worries you.