How many calories do I need a day?
Most adults need roughly 1,600–2,400 calories a day (women) and 2,000–3,000 (men), depending on age, size and activity, according to the Dietary Guidelines for Americans 2020–2025. For a personal estimate, enter your details below.
Last updated October 15, 2026 · General information, not personal medical advice
How your daily calories are estimated
First we estimate your BMR, the energy you use at rest, with the Mifflin-St Jeor equation:
Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Then we multiply by an activity factor: 1.2 for mostly sitting, 1.375 lightly active, 1.55 moderately active, 1.725 very active and 1.9 extra active. The result is your TDEE, the calories that keep your weight steady. This is the same formula the net calorie balance calculator uses, so the numbers match across the site.
BMR calculator: your resting energy
The calculator above also shows your BMR. It is usually the biggest part of your daily energy use. You never need to eat below it to make progress, and our calculator never suggests a target below your BMR.
Example daily calorie needs
| Example person | BMR | Mostly sitting | Lightly active | Moderately active | Very active |
|---|---|---|---|---|---|
| Woman, 30, 5′5″, 140 lb | 1,356 | 1,627 | 1,864 | 2,102 | 2,339 |
| Woman, 45, 5′4″, 160 lb | 1,356 | 1,627 | 1,864 | 2,101 | 2,339 |
| Man, 30, 5′10″, 175 lb | 1,760 | 2,112 | 2,420 | 2,728 | 3,036 |
| Man, 45, 5′11″, 195 lb | 1,792 | 2,150 | 2,463 | 2,777 | 3,091 |
Typical ranges from the Dietary Guidelines
The Dietary Guidelines for Americans 2020–2025 estimate 1,600 to 2,400 calories a day for adult women and 2,000 to 3,000 for adult men. The low end is for sedentary people and the high end for active people. Their table uses a reference woman of 5′4″ and 126 lb and a reference man of 5′10″ and 154 lb, so taller or heavier people can need more.
Want more on the healthy-ageing side? Read calories after 50 or visit Healthy Agers.
Frequently asked questions
How many calories do I need to maintain my weight?+
Your maintenance calories are your TDEE: resting energy (BMR) times an activity factor. For most adults it lands somewhere between about 1,600 and 3,000 kcal a day. Enter your details above for a personal estimate.
How many calories should a woman eat a day?+
The 2020–2025 Dietary Guidelines for Americans estimate 1,600 to 2,400 calories a day for adult women, from sedentary to active. Height, weight and age move you within that range, which is why a personal estimate is more useful.
How many calories should a man eat a day?+
The same guidelines estimate 2,000 to 3,000 calories a day for adult men, with the low end for sedentary days and the high end for active ones. Bigger, younger and more active bodies sit nearer the top.
What is the difference between BMR and TDEE?+
BMR is the energy your body uses at complete rest, just to keep you running. TDEE adds everything else: walking, chores, workouts and digestion. TDEE is the number to eat around if you want your weight to stay steady.
How accurate is this calculator?+
Mifflin-St Jeor is one of the most widely used equations, but it is a population average. Your real needs can differ by a few hundred calories. Use the result as a starting point and adjust based on how you feel over a few weeks.
Is my data saved or sent anywhere?+
No. Everything is calculated in your browser. Your entries are only remembered in your own browser (localStorage) so you do not have to type them again, and you can clear them any time.
Related
Sources: Mifflin MD, St Jeor ST et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51(2):241–247; Dietary Guidelines for Americans 2020–2025, Appendix 2: Estimated Calorie Needs (USDA/HHS); Harvard Health Publishing: Calorie counting made easy. The 2025–2030 Dietary Guidelines (Dietary Guidelines for Americans 2025–2030) no longer print a calorie table; they say needs depend on age, sex, height, weight and activity. The ranges above come from the 2020–2025 edition’s Appendix 2.