BMR Calculator

This tool estimates your Basal Metabolic Rate using the Mifflin-St Jeor equation, then multiplies it by an activity factor to produce Total Daily Energy Expenditure (TDEE). It also derives three target calorie levels: weight loss, maintenance, and weight gain, expressed in calories per day.

1. Select Gender (male or female). 2. Enter Age (1–150), Height (1–300), and Weight (1–500) as positive numbers. 3. Pick an Activity Level: sedentary, light, moderate, active, or extra. 4. Click Calculate. Missing fields show a 'fill all fields' error toast. Reset clears the form.

Mifflin-St Jeor base = 10 × weight + 6.25 × height − 5 × age, then male adds +5 and female subtracts −161. TDEE = BMR × multiplier where sedentary 1.2, light 1.375, moderate 1.55, active 1.725, extra 1.9. Goals use ±500 kcal/day: weightLoss = round(TDEE − 500), maintenance = round(TDEE), weightGain = round(TDEE + 500). All outputs are rounded to whole calories per day.