Calorie Calculator
Calculate your daily calorie needs based on your age, gender, height, weight, and activity level. Get personalized targets for maintenance, weight loss, and weight gain.
Uses the Mifflin-St Jeor equation -- the gold standard for BMR estimation
Calculate Your Daily Calories
Biological sex affects metabolic rate
Between 15 and 120 years
e.g., 5
e.g., 9
Between 66 and 661 lbs
Select the option that best matches your typical week
How to Use This Calorie Calculator
Enter Your Details
Choose your unit system (imperial or metric), then enter your age, gender, height, and weight.
Select Activity Level
Pick the activity level that best describes your typical week, from sedentary to extra active.
Get Your Targets
View your BMR, maintenance calories, and personalized targets for weight loss or gain.
The Mifflin-St Jeor Equation
Male BMR = (10 x weightkg) + (6.25 x heightcm) - (5 x age) + 5Female BMR = (10 x weightkg) + (6.25 x heightcm) - (5 x age) - 161The Mifflin-St Jeor equation was developed in 1990 and is widely considered the most accurate formula for estimating Basal Metabolic Rate (BMR) in healthy adults. BMR represents the minimum number of calories your body needs to sustain basic life functions at rest.
To find your Total Daily Energy Expenditure (TDEE), also known as maintenance calories, the BMR is multiplied by an activity factor:
TDEE = BMR x Activity MultiplierSedentary (little/no exercise): x1.200Lightly Active (1-3 days/week): x1.375Moderately Active (3-5 days/week): x1.550Very Active (6-7 days/week): x1.725Extra Active (intense daily): x1.900Key points about calorie estimation:
- Weight loss requires eating fewer calories than your TDEE -- a 500 cal/day deficit leads to roughly 1 lb/week loss
- Weight gain requires eating more than your TDEE -- a 500 cal/day surplus leads to roughly 1 lb/week gain
- Protein intake is important regardless of goal -- aim for 0.7-1g per pound of body weight to preserve muscle
- Individual variation means these are estimates -- track your weight over 2-4 weeks and adjust as needed
Activity Level Guide
Sedentary
x1.200Little or no exercise, desk job
Lightly Active
x1.375Light exercise 1-3 days/week
Moderately Active
x1.550Moderate exercise 3-5 days/week
Very Active
x1.725Hard exercise 6-7 days/week
Extra Active
x1.900Very hard exercise, physical job, or training twice/day
Frequently Asked Questions
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is a formula developed in 1990 that estimates Basal Metabolic Rate (BMR) -- the number of calories your body burns at rest. It is considered the most accurate predictive equation for estimating BMR in healthy adults. The formula uses your weight, height, age, and gender to calculate your base calorie needs.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body needs just to maintain basic functions like breathing and circulation while at rest. TDEE (Total Daily Energy Expenditure) includes your BMR plus the calories burned through physical activity and digestion. TDEE is your maintenance calorie level -- the amount you need to eat to maintain your current weight.
How many calories should I eat to lose weight?
A safe and sustainable rate of weight loss is 0.5 to 1 pound per week. To lose 1 pound per week, you need a calorie deficit of about 500 calories per day below your maintenance level. For a gentler approach, a 250-calorie deficit leads to about 0.5 pounds per week of weight loss. Always consult a healthcare professional before starting a calorie-restricted diet.
How accurate is this calorie calculator?
The Mifflin-St Jeor equation has been shown to be accurate within about 10% for most healthy adults. However, individual metabolism can vary based on genetics, body composition (muscle vs. fat), hormonal factors, and other variables. This calculator provides a good starting estimate -- monitor your weight over 2-4 weeks and adjust your intake based on actual results.
Should I eat back the calories I burn during exercise?
This calculator already accounts for exercise through the activity level multiplier. If you selected "Moderately Active" and your workouts match that description, your maintenance calories already include exercise. Only eat additional calories if you perform extra physical activity beyond what your selected activity level covers. Be cautious with exercise calorie estimates, as fitness trackers often overestimate calories burned.
Important Disclaimer
This calculator provides estimates for informational purposes only and should not be considered medical advice. The Mifflin-St Jeor equation is designed for healthy adults and may not be accurate for children, pregnant or breastfeeding women, elderly individuals, or those with certain medical conditions. Always consult with a healthcare professional, registered dietitian, or nutritionist before making significant changes to your diet or exercise routine.