BMR Calculator
Find out how many calories your body burns at complete rest.
Fill in your details to see your basal metabolic rate.
What is BMR?
Your basal metabolic rate is the energy your body needs just to stay alive — breathing, circulation, cell repair — before any movement at all. It typically accounts for 60–70% of the calories you burn in a day, which is why it is the foundation of every calorie target.
This calculator uses the Mifflin–St Jeor equation:
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Worked example: a 28-year-old woman, 162 cm and 60 kg: 10×60 + 6.25×162 − 5×28 − 161 = 1,312 kcal/day at complete rest.
From BMR to a daily target
BMR is only the resting half of the picture. Multiply it by an activity factor (1.2–1.9) to get your total daily energy expenditure — that is exactly what our calorie calculator does, and the macro calculator then splits the result into protein, carbs, and fat.
BMR while fasting
Short-term fasting — 16:8, or daily fasts during Ramadan — does not meaningfully lower your BMR. Metabolic slowdown only becomes a concern with prolonged, very low intake. During Ramadan, your resting needs stay the same; plan suhoor and iftar to cover them.
Frequently asked questions
What is a normal BMR?
Most adults fall between roughly 1,200 and 2,000 kcal/day depending on size, age, and sex. Larger and younger bodies burn more at rest; BMR declines gently with age.
Is BMR the same as the calories I should eat?
No. BMR is what you burn at complete rest. Your daily target is BMR multiplied by an activity factor — use the calorie calculator for the full number.
Does fasting lower my BMR?
Daily intermittent fasting, including Ramadan fasts, has little effect on BMR. Only prolonged severe restriction causes meaningful metabolic adaptation.
How can I increase my BMR?
Building muscle is the most reliable way — muscle tissue burns more energy at rest than fat. Strength training plus adequate protein raises your resting burn over time.
This tool provides general estimates, not medical advice. Consult a professional before major dietary changes.
Put your number to work
MyNutriRise builds your daily plan from this same math — then tracks every meal with an AI photo scan.