Fitness & Health Calculators

BMI, calories & everyday health metrics.

BMI CalculatorBMI in metric or imperial units, with WHO categories. Calorie CalculatorDaily calories to maintain, lose or gain weight at a pace you choose. TDEE CalculatorMaintenance calories plus fixed 10% and 20% deficit and 10% surplus targets. Body Fat CalculatorBody fat estimate from height, neck, waist and hip using the US Navy method. Macro CalculatorProtein, carb and fat grams from your daily calories, with presets or custom ratios. Sleep CalculatorBedtime and wake-up time counted in 90-minute sleep cycles, with recommended times highlighted.

Which health calculator should I use?

A quick weight check: the BMI Calculator compares weight with height. It does not measure body fat, which is what the Body Fat Calculator estimates from tape measurements.
Maintenance calories and quick targets: the TDEE Calculator shows maintenance calories with fixed 10% and 20% deficits and a 10% surplus.
A calorie target for a goal: the Calorie Calculator turns a pace in kilograms per week into a daily target and estimates the weeks to a target weight.
Planning your sleep: the Sleep Calculator works out what time to go to bed for a wake-up time, or when to wake up if you go to bed now, using 90-minute sleep cycles. For the background, read how many sleep cycles you need per night.
Splitting calories into nutrients: once you have a calorie target, the Macro Calculator converts it into grams of protein, carbohydrate and fat.

About Fitness & Health Calculators

Fitness & health calculators provide quick estimates for common measurements such as body mass index, calorie needs, body fat and daily macronutrient targets. They are designed to make the arithmetic easy to reproduce by showing the inputs used for each result, so you can explore how changes in age, height, weight, activity or other assumptions affect an estimate.

The BMI calculator uses height and weight to calculate a body mass index, while calorie and TDEE tools estimate energy needs from personal inputs and activity assumptions. The body-fat and macro calculators provide additional estimates that can help with general planning, and the sleep calculator estimates bedtimes and wake-up times from sleep cycles. Different formulas can produce different results, so the method and assumptions on each tool matter.

These calculators are informational tools, not medical diagnostic instruments. Individual health needs can depend on factors that a simple formula cannot capture, including medical history, medications, pregnancy, athletic training and other circumstances. For health decisions, symptoms, treatment or a personalized nutrition plan, use guidance from a qualified healthcare professional.

Use the calculators as a starting point: enter measurements carefully, review the assumptions, and avoid treating a single estimate as a definitive health assessment. Rechecking inputs and comparing results over time can be more useful than focusing on one isolated number.