HEALTH CALCULATOR
Calorie Calculator
Estimate how many calories you may need each day based on your age, sex, height, weight, and typical activity level. See your estimated BMR, maintenance calories, activity comparison, and mathematical calorie adjustments in one place.
Calculate Your Daily Calories
Estimate resting and maintenance calorie needs from your personal information.
Personal information
Daily Calories by Activity
Your BMR stays constant while the activity multiplier changes the estimated daily energy requirement.
Calorie Target Range
Mathematical examples around your estimated maintenance level.
Calculation Breakdown
See how the final maintenance estimate is produced.
Activity Level Reference
The same BMR produces different estimates as the assumed activity level changes.
| Activity | Multiplier | Description | Calories / day |
|---|---|---|---|
| Sedentary | × 1.200 | Little or no exercise | 2,039 |
| Lightly active | × 1.375 | Exercise 1–3 days/week | 2,336 |
| Moderately active | × 1.550 | Exercise 3–5 days/week | 2,633 |
| Very active | × 1.725 | Hard exercise 6–7 days/week | 2,930 |
| Extra active | × 1.900 | Very hard exercise or physical work | 3,228 |
What Is a Calorie Calculator?
A calorie calculator estimates how much energy your body may use each day based on a small set of personal measurements. Unlike a simple calorie lookup, it combines information such as age, height, weight, sex, and activity level to produce an individualized mathematical estimate.
The result can be useful as a starting point when thinking about maintenance calories, weight changes, or energy requirements. It should not be treated as a measurement of your exact daily energy expenditure.
If you want to understand the resting component separately, our BMR Calculator focuses specifically on basal metabolic rate. For a broader body-size screening measure, you can also use our BMI Calculator.
How Does the Calorie Calculator Work?
The calculator first estimates basal metabolic rate, or BMR. BMR represents the estimated energy required to support essential body functions at rest. The calculation then applies an activity multiplier to estimate daily maintenance energy needs.
This two-step approach is also why changing your activity level can have a substantial effect on the final estimate even when your age, height, and weight remain unchanged.
Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation for its BMR estimate. The equation uses your age, sex, height, and weight to estimate resting energy requirements before an activity multiplier is applied.
Formula for men
Formula for women
After the BMR estimate is calculated, the calculator multiplies it by the activity factor selected in the calculator above.
Activity Levels and Calorie Needs
Activity level is one of the most important assumptions in this calculation. The calculator uses five commonly used activity multipliers:
| Activity level | Multiplier | Typical description |
|---|---|---|
| Sedentary | 1.200 | Little or no exercise |
| Lightly active | 1.375 | Exercise 1–3 days per week |
| Moderately active | 1.550 | Exercise 3–5 days per week |
| Very active | 1.725 | Hard exercise 6–7 days per week |
| Extra active | 1.900 | Very hard exercise or physical work |
These categories are broad estimates rather than precise measurements. Two people with the same height, weight, and selected activity category can still have different real-world energy requirements.
BMR vs. Maintenance Calories
BMR and maintenance calories are related, but they are not the same number. BMR represents estimated resting energy use, while maintenance calories attempt to account for normal daily movement and activity.
For example, a person with a BMR of 1,700 calories who selects a moderate activity multiplier of 1.55 would have an estimated maintenance level of about 2,635 calories per day.
To estimate total daily energy expenditure more directly, use the TDEE Calculator is another useful related tool.
Calorie Deficit and Calorie Surplus
A calorie deficit means consuming fewer calories than your estimated maintenance level over time. A calorie surplus means consuming more than the estimated maintenance level.
The calculator intentionally presents the −500, −250, +250, and +300 values as mathematical adjustments around maintenance. They are displayed to help explain the relationship between maintenance calories and calorie targets, not as individualized diet prescriptions.
Example Calorie Calculation
Consider a 30-year-old man who is 175 cm tall, weighs 75 kg, and selects a moderately active lifestyle.
Applying the moderate activity multiplier of 1.55 gives:
This example is only an illustration of the calculation. Changing age, height, weight, sex, or activity level changes the result.
What Can Change Your Estimated Calorie Needs?
- Age: The equation changes the estimate based on age.
- Body weight: A larger body generally requires more energy to maintain.
- Height: Height is included in the BMR equation.
- Sex: The Mifflin-St Jeor equation uses different constants.
- Activity: The activity multiplier can substantially change the maintenance estimate.
- Body composition: Two people with identical weight can have different energy requirements because their body composition may differ.
- Daily movement: Walking, standing, occupational activity, and other movement can vary considerably between people.
Calorie Calculator vs. BMI Calculator
A calorie calculator and a BMI calculator answer different questions. Calorie calculations estimate energy requirements, while BMI uses height and weight to produce a body-mass index used as a broad adult screening measure.
If you are reviewing several health measurements, you can use our BMI Calculator together with the Body Fat Calculator and Ideal Weight Calculator for additional context.
How Accurate Is a Calorie Calculator?
A calorie calculator provides an estimate rather than directly measuring your energy expenditure. The equation itself is based on population data, while the activity multiplier is a broad assumption about your normal routine.
Real calorie requirements can vary because of body composition, exercise, non-exercise movement, metabolism, health, and other factors. Treat the result as a starting point rather than an exact number.
Who Should Use This Calculator?
This calculator is designed for general informational use by adults. It can help explain how basic measurements and activity assumptions affect an estimated calorie requirement.
Children and teenagers, pregnant people, people with certain medical conditions, and people with specialized nutritional requirements may need a different approach. A qualified healthcare or nutrition professional can provide individualized guidance.
Frequently Asked Questions
How many calories do I need each day?
Daily calorie needs vary between people. This calculator estimates maintenance calories from age, sex, height, weight, and selected activity level.
Is BMR the same as maintenance calories?
No. BMR estimates resting energy use. Maintenance calories are estimated by applying an activity multiplier to BMR.
What formula does the calculator use?
The calculator uses the Mifflin-St Jeor equation to estimate BMR and then applies the selected activity multiplier.
What activity level should I choose?
Choose the category that most closely represents your typical routine rather than your most active day.
Can I use the result as medical or diet advice?
No. The results are general mathematical estimates and are not individualized medical or nutrition advice.
Does it work with pounds and feet?
Yes. Select US Units and enter height in feet and inches and weight in pounds. The calculator converts those values internally before applying the equation.