Nutrition
Calorie Calculator
Compare 3 established BMR formulas side-by-side for a more informed calorie starting point.
Compare 3 established BMR formulas side-by-side for a more informed calorie starting point.
A calorie calculator estimates how many calories your body needs daily to maintain, lose, or gain weight. The calculation starts with your Basal Metabolic Rate (BMR) - the calories your body burns at complete rest - and multiplies it by an activity factor to determine your Total Daily Energy Expenditure (TDEE).
Different formulas have been developed over the years, each with its own strengths. Our calculator compares three of the most respected methods: Mifflin-St Jeor (most accurate for general population), Harris-Benedict (well-established classic), and Katch-McArdle (most accurate if you know your body fat percentage).
To get the most accurate Katch-McArdle result, calculate your body fat percentage first - it's the only formula that uses lean mass instead of total weight.
Considered the most accurate for the general population. Recommended by the Academy of Nutrition and Dietetics.
Originally published in 1919 and revised in 1984. Tends to overestimate calorie needs slightly for overweight individuals.
The most accurate formula if you know your body fat percentage. Uses lean body mass rather than total weight.
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little to no exercise, desk job |
| Light | 1.375 | Light exercise 1-3 days/week |
| Moderate | 1.55 | Moderate exercise 3-5 days/week |
| Very Active | 1.725 | Hard exercise 6-7 days/week |
| Extremely Active | 1.9 | Intense daily training or physical job |
When two or three formulas give you different calorie targets, that's not a flaw - it reflects honest uncertainty in estimating metabolism.
The "right" number is ultimately the one that produces your expected weight change over 2-3 weeks. Formulas give you a strong starting point - your body provides the final answer.
Here's how calorie needs vary across different profiles and goals:
Profile: Female, 30 years old, office worker
Stats: 65 kg, 165 cm, sedentary
TDEE: 1,680 kcal
Goal Calories: 1,344 kcal/day
Profile: Male, 35 years old, gym-goer
Stats: 80 kg, 178 cm, moderate activity
TDEE: 2,767 kcal
Goal Calories: 2,767 kcal/day
Profile: Male, 25 years old, athlete
Stats: 75 kg, 180 cm, very active
TDEE: 3,045 kcal
Goal Calories: 3,502 kcal/day
For most people, the Mifflin-St Jeor formula is the best starting point. If you know your body fat percentage accurately, the Katch-McArdle formula will be most accurate. The average of all formulas is usually the safest bet for beginners.
Each formula was developed using different research populations and methodologies. Differences of 100-200 calories between formulas are normal. Mifflin-St Jeor (1990) is most accurate for average adults, while Katch-McArdle accounts for body composition.
All BMR formulas are estimates based on population averages. Individual metabolism can vary by 10-15% due to genetics, hormones, and muscle mass. Use these numbers as a starting point, then adjust based on real-world results after 2-3 weeks.
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. Always use TDEE, not BMR, when planning your diet.
If you selected an activity level that includes your exercise, don't eat back additional exercise calories. If you selected "Sedentary" but exercise regularly, you can either increase your activity level or eat back roughly 50% of exercise calories.
Track your weight weekly for 2-3 weeks. For weight loss, expect roughly 0.25-0.75 kg/week depending on body size. For muscle gain, expect 0.25-0.5 kg/week. If progress differs significantly, adjust calories by 100-200 kcal.