Maintenance Calorie Calculator
Estimate how many calories a day keep your weight steady, from the equations the National Academies published in 2023, with the range most people with your numbers fall in.
Adults 19 and older.
Calories a day to keep your current weight
2,277
Estimated Energy Requirement for a 40-year-old low active woman (5 ft 4 in, 165 lb), from the 2023 National Academies equations. About 68 of 100 people with the same numbers need between 2,036 and 2,518 calories.
Weigh yourself for a few weeks: if your weight stays the same, this is your number; if it moves, adjust.
| Starting value for low active women | 575.77 |
|---|---|
| 7.01 × age 40 | −280.40 |
| 6.60 × height 162.6 cm | +1,072.90 |
| 12.14 × weight 74.8 kg | +908.59 |
| Calories a day to maintain your weight | 2,277 |
| 95 of 100 people with your numbers need | 1,804 to 2,749 |
| At complete rest (Mifflin-St Jeor 1990) | 1,403 |
| Activity level | Calories a day |
|---|---|
| Inactive | 2,111 |
| Low active | 2,277 |
| Active | 2,417 |
| Very active | 2,646 |
To lose weight, see the calorie deficit calculator; to split your calories into protein, carbs and fat, the macro calculator.
This is general information, not medical advice. Talk to a doctor about your own numbers.
How this is calculated
The National Academies of Sciences, Engineering, and Medicine set the Estimated Energy Requirement (EER), the average calories a day that keep an adult of a given age, sex, height, weight and activity level at a stable weight. Its 2023 report updated the equations from 2002 and 2005. The committee used studies with doubly labeled water, which it calls the benchmark for measuring how much energy people burn, and for the first time included people with overweight, obesity and chronic disease.
Each equation starts from a fixed number, subtracts an amount for each year of age and adds an amount for each centimeter of height and each kilogram of weight. There is one equation for each sex and each of four activity levels. The report’s own example: a 22-year-old woman, 165 cm and 63 kg, low active: 575.77 − 7.01 × 22 + 6.60 × 165 + 12.14 × 63 = 2,275 calories a day. In U.S. units, a 40-year-old low-active woman who is 5 feet 4 inches and 165 pounds needs about 2,277.
| Sex | Activity | Start | Age | Height | Weight |
|---|---|---|---|---|---|
| Women | Inactive | 584.90 | 7.01 | 5.72 | 11.71 |
| Women | Low active | 575.77 | 7.01 | 6.60 | 12.14 |
| Women | Active | 710.25 | 7.01 | 6.54 | 12.34 |
| Women | Very active | 511.83 | 7.01 | 9.07 | 12.56 |
| Men | Inactive | 753.07 | 10.83 | 6.50 | 14.10 |
| Men | Low active | 581.47 | 10.83 | 8.30 | 14.94 |
| Men | Active | 1,004.82 | 10.83 | 6.52 | 15.91 |
| Men | Very active | −517.88 | 10.83 | 15.61 | 19.11 |
Picking your activity level
The activity level is the ratio of the energy you burn in a day to the energy you burn at rest. The National Academies give these example days for people with desk jobs; other activities of similar effort count the same:
| Level | Ratio | Example day |
|---|---|---|
| Inactive | 1.0 to under 1.53 | Daily living only: about 30 minutes of walking plus about 90 minutes of light to moderate activity like housework |
| Low active | 1.53 to under 1.68 | Daily living plus 60 to 80 minutes of walking at 3 to 4 mph |
| Active | 1.68 to under 1.85 | Daily living plus 30 to 50 minutes of walking, 45 minutes of moderate cycling and 40 minutes of doubles tennis |
| Very active | 1.85 to under 2.50 | Daily living plus 45 minutes of moderate cycling, about 25 minutes of jogging and 60 minutes of doubles tennis |
“Inactive” does not mean bedridden: it is a normal day with some walking and housework but no exercise. The report itself says no reliable tool exists to sort one person into a level, so if you are between two, look at both rows in the result.
How exact is it?
The equation gives the average for people like you. Real needs vary even among people with the same age, height, weight and activity. The report puts the standard error for one person at 241 calories a day for women and 342 for men: about 68 of 100 people fall within one standard error of the estimate, and about 95 of 100 within 1.96 of them (about ±472 for women, ±670 for men). The National Academies’ advice is to watch your weight over time and adjust what you eat.
Resting energy, for comparison
The result also shows resting energy from the Mifflin-St Jeor equation (1990): 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women. That is what your body uses at complete rest. Many sites multiply it by factors from 1.2 to 1.9 for activity. We did not find a primary source for those factors, so this page uses the National Academies equations, which estimate the whole day directly.
Who this is not for
The equations are for adults 19 and older. The National Academies use separate equations for children and teens, from the second trimester of pregnancy, and while breastfeeding. The report also says the equations are not designed for losing or gaining weight, and it names people with extremely high activity as a group the equations do not specifically address. To plan a deficit, use the calorie deficit calculator, which starts here and explains the limits.
Sources
Checked against the sources below on .
- National Academies (NASEM): Dietary Reference Intakes for Energy (2023), Table S-1 equations and Chapter 7
- Health Canada: Equations to estimate energy requirement (the same 2023 equations, with activity ranges)
- Mifflin MD et al.: A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51:241–7
Questions people ask
How many calories do I burn a day?
It depends on age, sex, height, weight and activity. A 40-year-old low-active woman who is 5 feet 4 inches and 165 pounds needs about 2,277 calories a day to keep her weight, by the 2023 National Academies equations.
How many calories does an average woman or man need?
For the median U.S. adult woman (5 feet 3.5 inches, 161 pounds, age 50) the National Academies estimate 2,014 calories a day if inactive and 2,543 if very active. For the median man (5 feet 9 inches, about 192 pounds): 2,581 to 3,345.
What is the difference between BMR and maintenance calories?
BMR or resting energy is what your body uses at complete rest; maintenance calories add everything you do in a day. For the 40-year-old woman above, Mifflin-St Jeor gives about 1,403 at rest, against 2,277 for the whole day.
Which activity level should I choose?
Inactive is daily living only. Low active adds about 60 to 80 minutes of walking a day. Active adds walking plus about 85 minutes of cycling and tennis; very active adds more than 2 hours of vigorous activity. If you are between two, try both.
How accurate is a maintenance calorie calculator?
It gives the average for people like you. By the National Academies, about 95 of 100 women with the same numbers need within about 472 calories of the estimate, and men within about 670. Track your weight for a few weeks and adjust.