BMR and TDEE Calculator

BMR is rest. TDEE is the day you actually live

Basal metabolic rate is the energy your organs use at complete rest. Total daily energy expenditure multiplies that by an activity factor. A calorie target that is not tied to BMR or TDEE is only a guess. Eating far below TDEE, or far above it, can both fail to match your goal for different reasons. This page cannot tell you why any one person is not losing or gaining weight. BMR here is Mifflin-St Jeor, which dietetics texts often prefer over original Harris-Benedict (1919) for adult resting calories. The 1.2 to 1.9 activity steps are PAL multipliers applied to that BMR. They are the same PAL table used with Katch-McArdle and revised Harris-Benedict TDEE estimates. They are not 1919 Harris-Benedict activity coefficients.

Defaults: male, 30 years, 170 lbs, 70 inches, moderately active (multiplier 1.55). Weight in kilograms is 77.11. Height in centimeters is 177.8. BMR = 10 x 77.11 + 6.25 x 177.8 - 5 x 30 + 5 = 1,737 kcal. TDEE = 1,737 x 1.55 = 2,693 kcal. Loss at 80% is 2,154. Surplus at 115% is 3,097. BMI on those stats is 24.4, the middle of the standard healthy band, so no safety note fires.

Male BMR = 10*kg + 6.25*cm - 5*age + 5 (Mifflin-St Jeor)
Female BMR = 10*kg + 6.25*cm - 5*age - 161
TDEE = BMR x PAL (1.2, 1.375, 1.55, 1.725, 1.9)
Loss = TDEE x 0.80 · Gain = TDEE x 1.15

PAL labels: Sedentary 1.2 (desk, little training). Lightly Active 1.375 (1 to 3 sessions). Moderately Active 1.55 (3 to 5, the default). Very Active 1.725 (6 to 7 hard days). Extra Active 1.9 (physical job plus training). Pick the week you actually live, not the week you planned in January. Copy exports BMR, TDEE, both targets, BMI, and the PAL factor as plain text.

When the safety note is there on purpose

BMI under 18.5 with a 20% cut is a red flag, not a flex. BMI 35 and up still gets a TDEE number, but a large home deficit belongs with a clinician. If the loss target drops under 1,200 kcal, the banner says so even if BMI looks "fine." That floor is a common adult minimum in outpatient nutrition, not a law of physics. Female constants produce a lower BMR: same defaults with Female selected drop BMR by 166 kcal versus Male, so the 1,200 warning appears sooner on smaller frames.

Age is clamped 15 to 100. Weight minimum is 30 in the active unit. Imperial height minimum is 48 inches. Metric height minimum is 100 cm (the spec's 100 makes sense in centimeters, not inches). Invalid ranges disable copy and show n/a. Switching imperial to metric converts 170 lbs and 70 inches in place so you do not retype.

This is not a DEXA scan and not a thyroid panel. NEAT (fidgeting, walking to the store) is inside the activity multiplier, and that mapping is crude. If weight is not moving after a stretch at a planned target, common causes include logging error, an activity factor that does not match the week you actually live, water weight, or a medical issue. Recheck inputs, or talk with a clinician or registered dietitian. Do not treat a large extra cut as the default next step.

What to do with the calorie number next

Paste maintenance, loss, or surplus into the Macro Nutrient Calculator to get protein, carb, and fat grams. Hydration is a separate lever: use the Daily Water Intake Calculator so a cut does not turn into a headache from coffee and no water. Neither page replaces a registered dietitian if you have a medical condition, are pregnant, or have a history of disordered eating.

Recalculate when body weight changes by about 5% or when your job or training block changes. A 170 lb moderately active male who starts a warehouse shift is Extra Active, not Moderately Active with a hope. The badge on the TDEE card is there so the screenshot you send a coach includes the multiplier, not only the calorie total.

Frequently Asked Questions (FAQ)