Determine your daily caloric targets using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle equations, customized for weight loss, maintenance, or muscle gain.
BMR and TDEE vary between people and over time. Use the results as a general reference — individual needs may require professional evaluation.
These fields feed the BMR formulas and the activity factor.
Resting metabolism first; then the effect of activity.
Same value as the estimated TDEE. Doesn't guarantee weight maintenance.
Turns the scenario value above into a mathematical macronutrient split. Doesn't define individual nutritional needs.
Fill in the values, paste your text, or upload the file this tool works with.
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A BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure) calculator that compares Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle, simulates illustrative caloric scenarios, and suggests a macronutrient split — all calculated in the browser.
Enter age, weight, height, and activity level to see your Basal Metabolic Rate and Total Daily Energy Expenditure, compare the three scientific formulas, and simulate illustrative deficit, maintenance, and surplus scenarios.
BMR is the energy your body burns at complete rest, just to sustain vital functions. TDEE multiplies BMR by an activity factor (from ×1.2 for sedentary to ×1.9 for extremely active) to estimate a full day's expenditure, including exercise and general movement.
TDEE = BMR × activityFactorBy default, the tool uses Mifflin-St Jeor, considered the most accurate for most adults. As soon as you enter a body fat percentage, it switches to Katch-McArdle — based on your estimated lean mass — as the primary reference, since it tends to be more accurate for anyone who has that measurement.
All three formulas (Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle when available) stay visible in the comparison, so you can see the spread between them instead of trusting a single number.
These three values are just mathematical reference points — they don't account for health history, medication, or specific goals, which call for professional evaluation.
The protein, carb, and fat split is calculated from the selected scenario's value above (deficit, maintenance, or surplus), not from raw TDEE — switching scenarios also recalculates every macronutrient's grams.
protein_g = (calories × %protein) / 4; fat_g = (calories × %fat) / 9Switching between metric (kg, cm) and imperial (lb, ft/in) converts whatever you've already entered automatically, so you don't lose what you typed when changing systems.
Age, weight, height, and every other field are processed entirely in your browser — nothing is sent to a server or stored. BMR and TDEE are estimates based on population equations; they don't replace an evaluation from a dietitian or physician, especially for specific health conditions.
As soon as you enter a body fat %, the tool switches to Katch-McArdle, which calculates BMR from your estimated lean mass instead of total weight — generally more accurate for anyone who has that measurement available.
No — they're fixed, illustrative values (−300 and +250 kcal) used as a common reference, not an individual prescription. Real needs vary by health history, actual activity level, and specific goals.
They're equations built from different populations and decades. Mifflin-St Jeor (1990) is considered more accurate for today's population; the revised Harris-Benedict is older and tends to slightly overestimate BMR for some people.
Yes — the protein, carb, and fat grams are recalculated from the selected scenario's value (deficit, maintenance, or surplus), not from a fixed number.
Yes — weight and height convert automatically between kg/cm and lb/ft+in, so you don't need to retype anything when changing systems.
BMI shows up as a quick auxiliary reference (weight relative to height), but it doesn't feed into the BMR or TDEE calculation — those formulas use weight, height, age, and sex directly, not the BMI classification.
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