Free Health Calculators
Estimate your BMI, daily calorie needs and body fat percentage in seconds. Each calculator explains its method, runs in your browser, and needs no signup.
Last updated: November 2026
Weight, Calories and Body Composition
These calculators cover three common questions about body weight and fitness: how your weight compares with your height, roughly how many calories you use in a day, and how much of your weight may be fat.
BMI Calculator
Find your body mass index and adult BMI category, plus the weight range that corresponds to your height.
Calorie Calculator
Estimate your daily calories (BMR and activity level) and see targets for weight loss or gain.
Body Fat Calculator
Estimate body fat percentage from tape measurements with the U.S. Navy method, plus fat and lean mass.
Which Health Calculator Should I Use?
| If you want to… | Use |
|---|---|
| Check your weight against your height and see a healthy weight range | BMI Calculator |
| Estimate how many calories you use per day, or set a loss or gain target | Calorie Calculator |
| Estimate body fat percentage from neck, waist and hip measurements | Body Fat Calculator |
| Work out what percentage of your starting weight you have lost | Weight Loss Percentage Calculator |
How to Read These Estimates
They are estimates, not measurements
Each calculator applies a published formula to the numbers you enter. Real bodies vary, so treat the results as a starting point and a way to track your own trend over time, not as a diagnosis or a target that suits everyone.
Use more than one number
BMI looks only at height and weight, calorie needs depend on activity as well as body size, and a tape-measure body fat estimate depends on how carefully you measure. Looking at two or three of them together gives a fuller picture than any single figure.
Talk to a professional
If you are pregnant, under 18, managing a medical condition, or thinking about a big change to your diet or exercise, ask a doctor or registered dietitian before acting on any calculator result.
Frequently Asked Questions
What health calculators are available?
There are three health calculators: the BMI Calculator for body mass index and a healthy weight range for your height, the Calorie Calculator for estimated daily calorie needs and weight loss or gain targets, and the Body Fat Calculator for a tape-measure estimate of body fat percentage.
Are these health calculators free?
Yes. Every calculator is free to use as often as you like, with no signup and no download.
Is my health data stored or sent anywhere?
No. All calculations run in your browser. The weight, height and measurements you type are not sent to a server, stored or shared.
Can I use these calculators as medical advice?
No. The results are general estimates for information and fitness tracking. They do not diagnose any condition. For advice about your weight, diet or health, talk to a doctor, dietitian or other qualified clinician.
What is the difference between BMI and body fat percentage?
BMI is calculated from weight and height only, so it cannot tell muscle from fat. Body fat percentage estimates how much of your weight is fat. The two measures can disagree, for example for very muscular people, so each calculator page explains what its number does and does not show.
Which calculator should I start with?
Start with the BMI Calculator if you want a quick height-and-weight check, the Calorie Calculator if you want to estimate how much energy you use in a day, and the Body Fat Calculator if you have a tape measure and want to estimate body composition.
Last reviewed: November 2026 — descriptions verified against each calculator.