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Health & nutrition calculators.
BMI, calories, macros and more. Clear answers calculated privately in your browser.
Choose your calculator.
Clear, useful numbers to help you understand your body and plan your next step.
BMI Calculator
Body Mass Index from your height and weight.
BMR Calculator
Calories your body burns while completely at rest.
TDEE Calculator
Your total daily calorie needs based on activity.
Macro Calculator
Personal protein, carbohydrate and fat targets.
Body Fat Calculator
Estimate body-fat percentage with the U.S. Navy method.
Ideal Weight Calculator
Explore a healthy weight range for your height.
Protein Calculator
See how much protein you need each day.
Water Intake Calculator
Find a practical daily hydration target.
Which calculator should I use?
Start with BMI for a quick screen, then TDEE to see how many calories you burn a day. Turn that into a plate with the macro calculator, and check your protein target. Curious about composition? The body-fat calculator goes deeper than BMI alone.
Numbers are the easy part
Knowing your targets is step one, hitting them every day is the hard part. Gram Fit reads your meals from a photo, tracks your macros in seconds, and coaches you toward the goal these calculators point to.
Turn your numbers into a plan.
Gram Fit takes your targets and builds a plan that adapts every week. No spreadsheets, no guesswork.
These calculators provide general educational estimates, not medical advice. Speak with a doctor or dietitian before making significant changes, especially during pregnancy or when managing a health condition.