Daily calorie calculator
Mifflin-St Jeor equation × activity factor. Capped at the usual minimum (1,200 kcal women / 1,500 kcal men); going lower needs medical supervision. Estimates only.
Your daily calorie need is your resting burn (BMR) multiplied by an activity factor. A 30-year-old woman, 165 cm and 70 kg, with light activity needs about 1,950 kcal a day to maintain her weight; eating about 500 kcal less leads to roughly 0.5 kg of loss a week.
How the calculator works
It uses the Mifflin-St Jeor equation, which predicts resting energy use (BMR) well for most adults:
- Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
BMR is then multiplied by an activity factor, from 1.2 for mostly sitting to 1.9 for athletes or physical jobs. The result is your maintenance calories (also called TDEE): the amount that keeps your weight stable. Our guide to TDEE explains each part.
Worked example
A 30-year-old woman, 165 cm and 70 kg: 10 × 70 + 6.25 × 165 − 5 × 30 − 161 = 1,420 kcal BMR. With light activity (× 1.375) her maintenance is about 1,950 kcal. A 500 kcal deficit gives a target of about 1,450 kcal, and a gentler 250 kcal deficit about 1,700 kcal.
How fast should you lose weight?
About 7,700 kcal roughly equals 1 kg of body fat, so a 500 kcal daily deficit leads to around 0.5 kg a week. The CDC describes 0.5–1 kg (1–2 lb) a week as a healthy, sustainable pace. Faster loss is harder to keep up and more of it tends to be water and muscle.
The calculator never suggests going below 1,200 kcal for women or 1,500 kcal for men, because lower intakes make it hard to meet nutrient needs and should only happen under medical supervision. If you are pregnant or breastfeeding, under 18, or have a medical condition or a history of eating disorders, ask a doctor or dietitian before changing your intake.
Why your real number may differ
Equations are averages. Your body can burn 10% more or less than predicted, and your weight on the scale moves with water and food in your gut. Track your intake for two to three weeks, compare it with your weekly average weight, and adjust by 100–200 kcal if needed. Read why the scale may not move in a deficit if progress stalls.
Frequently asked questions
How many calories should I eat to lose weight?
Start about 250–500 kcal below your maintenance calories. That usually leads to 0.25–0.5 kg of loss a week. Do not go below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision.
What is the difference between BMR and TDEE?
BMR is what your body burns at complete rest. TDEE (maintenance) adds everything you do in a day, from walking to exercise, by multiplying BMR by an activity factor.
Which activity level should I choose?
Pick the level that matches a normal week, not your best week. Most people with desk jobs who exercise a few times a week fit 'light' (1.375). If unsure, choose the lower option.
How accurate is the Mifflin-St Jeor equation?
It is one of the most accurate equations for adults, but individuals can differ by around 10%. Use the result as a starting point and adjust after a few weeks of tracking.
Sources
This article is general information, not medical advice. If you have a health condition, are pregnant or under 18, talk to a doctor or registered dietitian before changing your diet.