BMR, TDEE, and a calorie deficit you can actually follow
Weight change is mostly energy in versus energy out. BMR and TDEE turn that idea into a daily calorie range without treating the result as a medical diagnosis.
BMR is the floor, TDEE is the day
Basal metabolic rate (BMR) estimates the calories your body uses at rest. Total daily energy expenditure (TDEE) multiplies that by an activity factor so walking, work, and training are included. Eating at TDEE tends to maintain weight; eating below it creates a deficit.
Common equations (Mifflin–St Jeor and similar) use sex, age, height, and weight. They are population estimates. Two people with the same stats can differ by a few hundred calories.
A moderate deficit beats an aggressive one
A 300–500 calorie daily deficit is a typical planning range. Larger cuts look faster on paper and are harder to keep, which is when tracking falls apart. Pair the calorie target with protein, sleep, and a step or training habit so the number is not the only lever.
BMI is a height-weight ratio, not a calorie plan. Use it as context, then set intake from TDEE.
Recalculate when weight changes
As weight drops, BMR drops a little. Recheck every few kilograms instead of locking one target for months. The BMI, BMR, and calorie calculators on Qalculators are a starting point, not a prescription.
BMR, TDEE, and a calorie deficit you can actually follow is part of the Health cluster on Qalculators. Use the related tools below to run the numbers instead of estimating by hand.
Results depend on the values you enter. Treat them as planning estimates and confirm important decisions with a professional when needed.