Health & Fitness Calculators

What belongs in the health and fitness category?

These calculators answer the four numbers most people want before changing their diet or training: your daily energy needs (TDEE), your basal metabolic rate (BMR), your body mass index (BMI), and how your calories should split into protein, fat, and carbs. All free, no account, no data saved.

What you can calculate

• TDEE — total daily energy expenditure, including activity, for weight loss, maintenance, or muscle gain.
• BMR — basal metabolic rate: the calories your body burns at rest, with Mifflin-St Jeor or Harris-Benedict formulas.
• BMI — body mass index with a visual gauge against the WHO categories.
• Macros — split any calorie target into protein, fat, and carb grams, including balanced, low-carb, high-protein, and keto presets.

How to use the results

1. Start with BMR to know your baseline, then TDEE to include daily activity — that’s the number to eat around for maintenance.
2. For weight change, adjust from TDEE: roughly a 500-calorie daily deficit for about a pound a week, or a surplus on top of TDEE to build muscle.
3. Take BMI as a screening figure, not a verdict — it doesn’t separate muscle from fat, so read it alongside the gauge and your own context.
4. Feed your calorie target into the macro calculator to turn it into grams of protein, fat, and carbs you can actually shop and cook against.

TDEE, BMR, BMI, macros — what’s the difference?

BMR is the calorie floor (resting burn), TDEE is BMR plus everything you do (the number that matters for your weight), BMI is a height-to-weight ratio that screens body size, and macros are the breakdown of calories into nutrients. Use BMR and TDEE together to pick a calorie target, then macros to hit it.

Common mistakes

• Eating to BMR instead of TDEE. BMR is the resting floor; eating exactly to it is usually an unintended deficit.
• Overestimating activity. Choosing “very active” when you exercise twice a week inflates TDEE and slows weight loss.
• Trusting BMI alone. Athletes and very muscular people can read “overweight” while being lean — use the number as context, not a label.

These numbers are estimates, not prescriptions — for anything medical, talk to a doctor or dietitian. If you’re also tracking the money side of a health goal, the finance calculators handle gym budgets and grocery planning alongside.