Calorie Calculator
Estimate your daily calorie needs from your age, height, weight and activity level. Compare maintenance calories with a goal-based estimate for adults.
Your estimate
Estimated daily calorie target
Maintenance vs. goal target
Bars use the larger of these two values as the comparison scale. Exact values are printed alongside each bar.
Review this estimate: The selected target is unusually low (below 1,000 kcal/day). This is a caution flag, not a universal safe/unsafe threshold or a recommended minimum. Do not treat this result as a personal dietary prescription; seek individualized advice from a qualified healthcare professional.
How your estimate was calculated
These are estimates, not direct measurements. BMR is not automatically the amount you should eat each day, and a target below BMR is not by itself a diagnosis or a universal safety boundary.
How to use this calorie calculator
Enter your age, choose the equation parameter, add your height and weight, and select the activity description that most closely fits your usual routine. Choose a goal and select “Calculate Calories.” Switch between metric and imperial units at any time; valid entered measurements convert when the system changes.
What is a calorie calculator?
A calorie calculator estimates how much food energy a person may use in a day. This tool estimates resting energy needs and then applies an activity multiplier to approximate total daily energy expenditure. Individual needs can be higher or lower than the result.
How does this calorie calculator work?
It uses the Mifflin–St Jeor equation to estimate resting energy expenditure from weight, height, age, and the selected sex-specific equation variant. It then multiplies that estimate by an activity factor to estimate total daily energy expenditure. The activity factors are practical approximations rather than measurements of your actual movement or metabolism.
What is BMR?
Basal metabolic rate (BMR) is commonly used to describe the energy the body needs to support basic functions at rest. The equation in this calculator predicts resting energy expenditure; it does not measure your metabolism in a laboratory. BMR is not a complete daily eating target because everyday movement, digestion, and activity also use energy.
What is TDEE?
Total daily energy expenditure (TDEE) is an estimate of the energy used across a typical day. In this calculator, TDEE is estimated by multiplying predicted resting energy expenditure by the chosen activity factor. If your routine changes, your energy needs may change too.
How many calories do you need each day?
There is no single daily calorie number that is right for everyone. Energy needs vary with body size, age, activity, physiology, health, and other factors. Use this result as a starting estimate, not a measurement or a rule that overrides hunger, symptoms, medical advice, or individual nutritional needs.
Calories for weight loss or weight gain
A deficit means a planned intake below estimated maintenance, while a surplus means a planned intake above it. This tool uses a user-adjustable daily difference, initially 300 kcal/day. Real-world changes are not perfectly linear, and the result does not guarantee a particular rate of weight loss or gain. Avoid aggressive restriction and seek individualized support when appropriate.
Limitations and health information
This calculator is intended for general information for adults aged 18 and over. It is not designed for teenagers, pregnant or breastfeeding people, competitive athletes with specialized needs, or people who need nutrition support for a medical condition. If you have a history of disordered eating, an eating disorder, or specific health or nutrition concerns, consult a qualified healthcare professional. Do not use this estimate as a diagnosis or individualized treatment plan.
Frequently asked questions
1. What is a calorie calculator?
It uses details such as age, height, weight, and activity to estimate daily energy needs. Estimates differ from direct measurement and should be interpreted as a guide.
2. How many calories should I eat per day?
Your needs depend on your body, activity, health, and goals. This calculator provides an estimate, not an individualized prescription; a qualified dietitian or clinician can help with personal needs.
3. What is the difference between BMR and TDEE?
BMR is an estimate of resting energy expenditure. TDEE estimates total daily energy expenditure by applying an activity factor to the resting estimate.
4. How accurate is this calorie calculator?
It applies a published predictive equation, but individual results can differ because equations and activity multipliers cannot account for every person's physiology or daily movement.
5. How does physical activity affect calorie needs?
Movement and exercise generally increase energy expenditure. The activity factor is a broad approximation, so choose the category that best represents your overall routine and revisit it when your routine changes.
6. Can I use pounds, feet, and inches?
Yes. Select Imperial (lb, ft, in). Valid measurements convert to the calculator's internal metric units before the equation is applied.
7. Can I use kilograms and centimeters?
Yes. Select Metric (kg, cm) and enter your weight in kilograms and height in centimeters.
8. How do I estimate calories for weight loss?
Select “Lose weight” and choose a daily adjustment. The calculator subtracts that amount from estimated maintenance calories; the result is not a guarantee, and aggressive restriction is not recommended.
9. How do I estimate calories for weight gain?
Select “Gain weight” and choose a daily adjustment. The calculator adds it to estimated maintenance calories. Individual goals and nutrition needs are best considered with a qualified professional.
10. Should I eat fewer calories than my BMR?
BMR is not a universal minimum intake or a direct eating prescription. Do not make decisions from the BMR number alone; seek professional guidance for a suitable intake, especially if your target is unusually low.
11. Can teenagers use this calculator?
No personalized estimate is provided for people under 18. Children and teenagers have different growth and nutrition needs and should seek guidance from a qualified healthcare professional.
12. Can pregnant or breastfeeding people use these results?
This general adult calculator is not designed for pregnancy or breastfeeding. Energy and nutrition needs in these situations should be discussed with an appropriate healthcare professional.
13. Why might my actual calorie needs differ from the estimate?
Equations may not fully account for body composition, health, medication, genetics, training, everyday movement, or changes over time. Activity categories are also subjective.
14. Does this calculator store my personal information?
This widget performs its calculations locally in your browser and contains no code to transmit or save your entries. Your website's other plugins, analytics, or hosting configuration operate separately and are not controlled by this widget.
References for further reading
- Mifflin et al. (1990), “A new predictive equation for resting energy expenditure in healthy individuals” — the original research paper describing the equation.
- US National Institute of Diabetes and Digestive and Kidney Diseases: Body Weight Planner information — adult-use limitations and health disclaimer.