Calorie Calculator

This calculator estimates Basal Metabolic Rate (BMR) with the Mifflin–St Jeor equation, multiplies by an activity level to estimate Total Daily Energy Expenditure (TDEE), then adjusts for lose, maintain, or gain goals. Everything runs locally in your browser — your inputs are not uploaded to produce the result.

BMR is an estimate of calories burned at rest. TDEE adds movement: sedentary desk work through to hard daily training. Activity multipliers are population averages — two people with the same stats can differ based on job, NEAT (fidgeting and walking), and training style.

A common fat-loss starting point is about 500 kcal below maintenance, often described as roughly 0.5 kg (about 1 lb) per week. Aggressive deficits are harder to sustain and can affect training and hormones. Surpluses for muscle gain are usually smaller than people expect once protein and progressive training are in place.

Age, sex, height, and weight feed the BMR formula. Be honest about activity — overestimating steps and workouts is the most common reason estimates feel “too high.” Recalculate after significant weight change; needs fall as you get lighter.

Nutrition needs vary with health conditions, medications, and life stage. Use Calorie Calculator for planning ballparks, then confirm personalised advice with a registered dietitian or clinician when it matters for your health.