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Calorie Calculator
Calculate your exact daily calorie needs using the Mifflin-St Jeor equation — the gold standard for BMR estimation. Supports metric and imperial units.
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TDEE Calculator
Calculate your Total Daily Energy Expenditure across 5 activity levels. The foundational number for any evidence-based nutrition plan.
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BMI Calculator
Calculate Body Mass Index with a full healthy-weight range breakdown. Includes WHO classification, limitations, and body composition context.
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Calorie Deficit Calculator
Calculate the precise calorie deficit and timeline to reach your target weight. Safe, sustainable, and adjusted for metabolic adaptation.
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Body Fat Calculator
Estimate body fat percentage using the US Navy circumference method — validated and accurate without gym equipment or body fat calipers.
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Ideal Weight Calculator
Calculate your ideal body weight across four peer-reviewed formulas: Hamwi, Miller, Robinson, and Devine — with a personalised healthy range.
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Free nutrition
calculators — science
backed.
Calculate calories, macros, TDEE, BMI, body fat, protein intake, keto macros, recipe nutrition, and more — instantly, using peer-reviewed formulas from Mifflin-St Jeor, ACSM, ISSN, and USDA. Free forever, no account needed.
Instant results
Every calculator updates live as you type. No loading screens, no button to press — results appear in real time.
Science-backed only
Every formula traces to a named, peer-reviewed source. Mifflin-St Jeor, ACSM, ISSN, USDA — never a black-box algorithm.
Visual & actionable
Colour-coded macro bars, body composition charts, and training percentage tables make results immediately usable.
Permanently free
All 18 calculators, every feature, every update — free forever. No signup, no paywall, no ads in your results.
What are you trying to figure out?
Every nutrition tool you need,
all in one place.
From basic calorie counting to advanced body composition analysis — all calculators are science-backed, instant, and permanently free.
Results in under 60 seconds.
Pick your calculator
Choose from 18 free tools across 4 categories — body & weight, macros & diet, fitness, and advanced metrics. All on one platform.
Enter your measurements
Input height, weight, age, and activity level. All calculators support both metric (kg/cm) and imperial (lbs/ft/in) units.
Get instant results
Results appear live as you type — no button press, no loading screen. Follow in-tool links to build your full nutrition picture.
Every result traces to a named, peer-reviewed source.
MacrosMeasure never uses proprietary algorithms or black-box scoring. Every calculation uses a published, citable formula — Mifflin-St Jeor for BMR, ACSM MET values for calorie burn, ISSN guidelines for protein, and USDA FoodData Central for nutrition data.
Results are mathematical estimates based on validated population equations, not clinical diagnoses. For personalised medical nutrition therapy, consult a registered dietitian.
All formulas are reviewed against their original published source annually. Mifflin-St Jeor (1990), US Navy method (Hodgdon & Beckett, 1984), Epley (1985), ACSM Compendium (Ainsworth et al., 2011). Read our methodology →
Nutrition questions, answered instantly
Use the Mifflin-St Jeor BMR equation — multiply by your activity factor to get TDEE. Our Calorie Calculator does this instantly. Most adults need 1,600–3,000 kcal/day.
Calculate calories →Macros (macronutrients) are protein, carbohydrates, and fat. Your macro targets are a percentage split of your daily calorie needs, adjusted for your goal (fat loss, muscle gain, maintenance).
Calculate macros →TDEE (Total Daily Energy Expenditure) is the total calories you burn daily — BMR × activity factor. It is the most important number for weight management and nutrition planning.
Calculate TDEE →Research supports 1.6–2.4 g per kg bodyweight for most active adults. Sedentary individuals need 0.8–1.0 g/kg. Higher intake (1.8–2.4 g/kg) is recommended during fat loss to preserve muscle.
Calculate protein →The US Navy circumference method uses neck, waist, and hip measurements to estimate body fat — no calipers or equipment needed. Accurate to within ±3% for most people.
Calculate body fat →Keto fixes net carbs at 20–50 g/day to induce ketosis, then allocates remaining calories to fat (65–80%) and protein (15–25%). Standard macros allocate carbs as 45–65% of calories.
Calculate keto macros →BMR (Basal Metabolic Rate) is the calories your body burns at complete rest to sustain vital functions. TDEE multiplies BMR by an activity factor to give your real-world daily calorie burn.
Calculate BMR →Enter each ingredient and its quantity into the Recipe Nutrition Calculator. It pulls live data from USDA FoodData Central and returns a full macro and micronutrient breakdown per serving.
Analyse my recipe →Enter the weight lifted and the number of reps completed. The calculator applies the Epley, Brzycki, and Lander formulas and returns your estimated 1RM with a full training percentage table.
Calculate 1RM →Take control of your nutrition today.
All 18 calculators — from the calorie calculator to the keto macro calculator — are free, instant, and require no account or subscription.
Free forever · No signup required · Results in under 60 seconds · Science-backed formulas