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Formula named on every pageMifflin-St Jeor, BMI and more

Category 03 of 12 · Calories, macros, BMI

Health Calculators

Our health calculators turn established formulas into quick, explained estimates: how many calories you burn, how much fat and other nutrients you need, the weight that matches a target BMI, your cholesterol ratios and your score on military fitness tests.

They give general estimates for healthy adults and are not medical advice. If you are pregnant, under 18 or managing a health condition, talk to a doctor or registered dietitian first. See our Disclaimer.

14live calculators
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01Calories and energy

Estimate your daily energy needs from your size and activity level. · 2 live

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TDEE Calculator

Estimate your total daily energy expenditure with the Mifflin-St Jeor equation and activity multipliers.

02Nutrition and diet

Set targets for fat, nutrients and keto macros. · 3 live

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Fat Intake Calculator

Find your daily fat target in grams from your calories and goal, plus saturated fat limits, omega-3 needs.

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DRI Calculator

Get your Dietary Reference Intakes – RDA, AI and Upper Limits.

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Keto Calculator

Calculate daily keto macros from your age, sex, height, weight, activity and goal.

03Body measurements

Goal weight, body shape and face shape from your measurements. · 3 live

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Reverse BMI Calculator

Enter your height and a target BMI to find the matching body weight in kg or lb.

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Body Shape Calculator

Enter shoulder, bust, waist and hip measurements to see your body shape.

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Face Shape Calculator

Measure forehead, cheekbones, jaw and face length to find your face shape.

04Heart health

Understand your cholesterol results and how much blood your heart pumps. · 2 live

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Cholesterol Ratio Calculator

Calculate your total cholesterol to HDL ratio, LDL/HDL, triglyceride/HDL and non-HDL cholesterol in mg/dL or mmol/L.

05Pregnancy

Population statistics about twin pregnancies. · 1 live

06Military fitness tests

Unofficial score estimates for training. · 2 live

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Navy PRT Calculator

Estimate your Navy PRT points for push-ups, forearm plank and cardio.

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ACFT Calculator

Score the Army Fitness Test (AFT) that replaced the ACFT: five events, combat (350) and general (300) standards.

07Lifestyle

See what a habit costs you – and what quitting saves. · 1 live

Quick guide

Which calculator do I need?

Match what you’re trying to do with the right tool.

If you’re…Planning calories for weight loss or gain
UseTDEE Calculator (or Mifflin-St Jeor for BMR only)
If you’re…Following keto
UseKeto Calculator, then Fat Intake Calculator to check fat targets
If you’re…Setting a goal weight
UseReverse BMI Calculator
If you’re…Reading a cholesterol test
UseCholesterol Ratio Calculator
If you’re…Preparing for a Navy or Army fitness test
UseNavy PRT or ACFT Calculator

How we build and check these calculators

Every calculator on Tuff Search shows the formula or method it uses, a worked example and its limits, and lists its sources where facts matter. Health, money and legal-rule pages are checked against official or peer-reviewed sources and dated. Read how we build and review calculators in our Editorial Policy.

Results are estimates for information only and are not professional advice. Read our Disclaimer.

FAQ

Frequently asked questions

Short answers about the health calculators.

Need a calculator we don’t have?

We add new calculators regularly. Email suggestions@tuffsearch.com with the calculation you need.

New calculator ideassuggestions@tuffsearch.com

No. They give estimates based on published formulas and guidelines. Use them to prepare questions for your doctor or dietitian, not to diagnose or treat anything.

The Mifflin-St Jeor equation, which research has found to be among the most accurate for estimating resting energy use in healthy adults, multiplied by an activity factor.

Yes – most health calculators accept kilograms or pounds and centimetres or feet and inches.

No. They are unofficial estimates for training. Your official score is the one recorded by your unit or Command Fitness Leader using the current published tables.

Whenever the guidance they rely on changes, and at least once a year. Each page shows its last review date and sources.

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