Free tool
Find the number of calories your body uses in a day. Then see how your meals add up against it.
No account needed. What you enter stays on this device.
Answer a few questions. The estimate uses the 2023 energy equations from the National Academies, the science behind the current U.S. nutrient reference values.
Your estimated daily calories
0calories a day
0 calories a day is your goal number.
This tool does not set goals under 1,200 calories a day for women or 1,500 for men. Eating less than that calls for guidance from your health care professional.
Move the slider to try a different daily number.
Daily guide amounts for your goal number.
Tap what you ate. Calories, protein, carbs and fat come from USDA food data.
Estimated total today
0calories
Guide ranges for adults: 45% to 65% of calories from carbs, 20% to 35% from fat and 10% to 35% from protein.
| Food | Meal | Amount | Calories | Basis and source |
|---|
Log a few days and patterns start to show. Your weekly average tells you more than any single day.
Use the same scale at the same time of day. Day to day changes are mostly water.
Your daily calorie number: an equation that uses your age in years, height in centimeters and weight in kilograms. There is one equation for each sex and activity level. All eight are listed below.
Your goal number: your daily number minus 250 or 500 calories to lose weight, or plus 250 to gain.
Calories in a food: calories per 100 g × grams eaten ÷ 100.
Example only: a woman who is 45 years old, 165 cm tall, weighs 70 kg and is low active. 575.77 − (7.01 × 45) + (6.60 × 165) + (12.14 × 70) = about 2,199 calories a day.
| Activity level | Men, 19 and older | Women, 19 and older |
|---|---|---|
| Inactive | 753.07 − 10.83A + 6.50H + 14.10W | 584.90 − 7.01A + 5.72H + 11.71W |
| Low active | 581.47 − 10.83A + 8.30H + 14.94W | 575.77 − 7.01A + 6.60H + 12.14W |
| Active | 1,004.82 − 10.83A + 6.52H + 15.91W | 710.25 − 7.01A + 6.54H + 12.34W |
| Very active | −517.88 − 10.83A + 15.61H + 19.11W | 511.83 − 7.01A + 9.07H + 12.56W |
A is age in years. H is height in centimeters. W is weight in kilograms. Results are calories a day.
The National Academies of Sciences, Engineering, and Medicine published these equations in 2023. They come from studies that used doubly labeled water. That lab method measures the calories people burn while living their normal lives.
No equation can know your body exactly. In the studies behind these equations, the typical miss was about 340 calories a day for men and about 250 for women. That is why you see a range next to your number.
Use your number as a starting point. If your weight holds steady for a few weeks, your real number is close to what you eat.
The tool also runs the Mifflin-St Jeor equation from 1990. It estimates the calories your body uses at rest. A 2005 review of four common equations found it the most reliable of the group.
We multiply that resting number by a typical activity factor for your level: 1.4, 1.6, 1.75 or 2.05. When the two methods land close together, you can feel better about the estimate.
An old rule says 3,500 calories equal one pound. It predicts a straight line. Real bodies bend that line. A lighter body uses fewer calories, so the same eating plan brings smaller changes as time goes on.
Researchers at the National Institutes of Health described this in 2011. Their rule of thumb: a lasting change of 10 calories a day shifts weight by about one pound over time. The change is slow. About half arrives in the first year, and nearly all of it within three years.
The chart in this tool draws one smooth curve through those published points. It is a simple model. The NIH Body Weight Planner uses a fuller one.
The CDC notes that people who lose about 1 to 2 pounds a week are more likely to keep the weight off. A 2013 guideline from U.S. heart and weight experts suggests eating 500 to 750 fewer calories a day. It lists 1,200 to 1,500 calories a day for women and 1,500 to 1,800 for men as typical plans.
For that reason, this tool never sets a goal under 1,200 calories a day for women or 1,500 for men.
It also will not set a weight loss goal when your body mass index is under 18.5, the standard cutoff for underweight in adults.
Food values come from the USDA National Nutrient Database for Standard Reference, Release 28 (SR28). Each result lists the USDA record number, so you can check it.
Restaurant, fast food and packaged dishes are marked “≈ Estimate” because recipes and brands vary. When you have the package, entering the label values is the most accurate choice.
Food library version 2026.11-c1, built 2026-11-12.
This tool is for adults 19 and older. Talk with your health care professional before you change how you eat if any of these apply to you:
This calculator does not send what you enter to us. If you turn on Remember me on this device, your numbers are saved in this browser only. You can erase them at any time.
It depends on your age, sex, height, weight and activity. The Dietary Guidelines for Americans, 2020 to 2025, estimated 1,600 to 2,400 calories a day for adult women and 2,000 to 3,000 for adult men. Use the calculator above for your own number.
A deficit means you eat fewer calories than your body uses. Eating 500 fewer calories a day is a common starting point in clinical guidelines.
For many adults it is too little. Guidelines list 1,200 to 1,500 calories a day as a weight loss range for women and 1,500 to 1,800 for men. Going under those amounts should involve your health care professional.
A lighter body uses fewer calories. The gap between what you eat and what you burn shrinks, so change slows. The 12 month chart in this tool shows that curve for your numbers.
They are averages from USDA lab data. Your portion, brand and recipe will differ. Weighing a food once or twice helps you learn what your usual portion looks like.
A week of logging shows where your calories come from. Coming back each day builds your weekly average, which tells you more than any single day.
This calculator gives estimates for education. It does not diagnose, treat or prevent any condition, and it is not medical advice. The estimates are for adults 19 and older who are not pregnant or breastfeeding. Food values are averages, and the foods you eat may differ. If you have a health condition or take medicine, ask your health care professional what calorie goal is right for you. Read our full medical disclaimer.
On the Nutrition Facts label, find the Calories line. Use the number listed per serving.
