Calorie Calculator
Find out how many calories you need each day to lose, maintain, or gain weight. This calculator estimates your BMR with the Mifflin-St Jeor equation, multiplies by your activity level to get your maintenance calories (TDEE), then adjusts for your goal so you get a daily calorie target you can actually eat to.
Formula
Target = TDEE + goal_delta
TDEE = BMR (Mifflin-St Jeor) × Activity factor
- Your BMR (calories burned at rest) uses the Mifflin-St Jeor equation: 10×weight(kg) + 6.25×height(cm) − 5×age, then +5 for men or −161 for women.
- Your TDEE (maintenance calories) is BMR multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active).
- Your target is TDEE plus or minus a calorie adjustment for your goal — a deficit to lose weight or a surplus to gain.
- About 7,700 kcal equals roughly 1 kg of body fat, so a 500 kcal/day deficit is about 0.5 kg per week.
- The target never drops below 1,200 kcal/day, a common floor for safe, sustainable dieting.
- These are estimates — track your weight for 2–3 weeks and adjust if the scale isn't moving as expected.
30-year-old man, 80 kg, 175 cm, moderately active, losing weight
Inputs
- Sex: male
- Age: 30 years
- Weight: 80 kg
- Height: 175 cm
- Activity Level: 1.55
- Goal: loss
BMR ≈ 1,749 kcal. × 1.55 activity ≈ 2,711 kcal maintenance (TDEE). With a 500 kcal deficit, the target is about 2,211 kcal/day for roughly 0.5 kg of loss per week.
Frequently asked questions
How many calories should I eat to lose weight?
Eat below your maintenance (TDEE). A 500 kcal/day deficit loses about 0.5 kg per week; 250 kcal/day is a gentler 0.25 kg per week. Avoid dropping below ~1,200 kcal/day without medical guidance.
What is TDEE?
Total Daily Energy Expenditure — the calories you burn in a day including activity. It's your BMR multiplied by an activity factor, and it's the number you'd eat to maintain your current weight.
Is the Mifflin-St Jeor equation accurate?
It's one of the most accurate BMR formulas for the general population, but it's still an estimate. Real needs vary with muscle mass, genetics, and how active you truly are, so use your weight trend to fine-tune.
Why is there a 1,200 calorie minimum?
Eating too little can cost you muscle, slow your metabolism, and leave you short on nutrients. The 1,200 kcal floor is a common safety guideline — go lower only under medical supervision.
How fast can I safely lose weight?
About 0.5–1 kg (1–2 lb) per week is a sustainable pace. Faster loss usually means losing more muscle and water and is harder to maintain.
Related calculators
TDEE Calculator Calculate your Total Daily Energy Expenditure (TDEE) — the total calories you burn in a day including exercise. This is your maintenance calorie number. BMR Calculator Calculate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation. Enter your sex, age, weight, and height to see your daily resting calorie needs. Calorie Deficit Calculator See how fast you'll lose weight from a calorie deficit. Enter your maintenance calories (TDEE) and how much you plan to eat each day, and this calculator shows your daily deficit plus your projected weekly and monthly weight loss — and how long it takes to drop each kilogram. Macro Calculator Macro Calculator is a health and wellness calculator that helps you calculate macro values from your input data. The formula used is: Protein = 30% of target calories ÷ 4\nCarbs = 40% of target calories ÷ 4\nFat = 30% of target calories ÷ 9. Enter values using the units shown next to each input field (e.g. kg, cm, years).