How to use the Calorie Calculator
- 1 Choose metric or imperial units and enter your age, height and weight.
- 2 Select the sex coefficient used by the equation and the activity level that best describes your usual week.
- 3 Read your estimated daily calories for weight maintenance and the resting energy estimate.
How many calories do I need each day?
Daily calorie needs vary with body size, age and activity. This calculator estimates the calories needed to maintain your current weight using your age, height, weight and a typical activity level. It also shows an estimate of the energy your body uses at rest.
How this calorie calculator works
The estimate uses the Mifflin–St Jeor equation to estimate resting energy, then applies a broad activity factor to account for movement and exercise. The equation uses weight, height, age and a male or female coefficient. If you choose imperial units, pounds and inches are converted before the estimate is calculated. The original research developed an equation to predict resting energy use in healthy adults (study record on PubMed).
Activity levels are approximate. Your work, commuting, regular walking and exercise all contribute to daily movement, and the same activity label can mean different things for different people. Use the level that most closely describes your usual routine, not just an unusually active or quiet day.
What does the result mean?
The larger number is an estimated daily calorie intake for weight maintenance. The BMR figure is an estimate of energy used at rest and does not include all activity. These values are starting estimates, not precise measurements or personalized nutrition instructions. Actual needs vary with body composition, health, medications and other factors.
General information for adults
This calculator is intended for general information for adults. It does not diagnose a health condition or prescribe a diet. Energy needs during growth, pregnancy, illness or recovery can be different; ask a qualified healthcare professional for individualized guidance.
Frequently asked questions
How many calories do I need to maintain my weight?
It varies by person. This calculator estimates a starting daily amount from age, height, weight and activity, but it is not a direct measurement.
Which formula does this calorie calculator use?
It estimates resting energy with the Mifflin–St Jeor equation and applies an activity factor to estimate daily energy use.
What is the difference between BMR and daily calorie needs?
BMR estimates energy use at rest. Daily calorie needs also include movement and exercise, so the maintenance estimate is usually higher.
How accurate is the calorie estimate?
It is a rough estimate, not a measurement. Activity labels and individual energy needs vary, so actual requirements may differ.
Can children or teenagers use this calculator?
No. It is intended for adults. Energy needs during growth or other health circumstances should be discussed with a qualified healthcare professional.
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