How Many Calories Should I Eat a Day? Ranges and Your Own Number

The short answer

Most adult women need somewhere between 1,600 and 2,400 calories a day to keep their weight steady, and most adult men need between 2,000 and 3,000. Those are the ranges in the Dietary Guidelines for Americans 2020-2025 (Appendix 2). Where you land depends on your age, sex, height, weight and how much you move.

To narrow that down to your own number, estimate the calories you burn at rest, multiply by your activity level, then add or subtract for your goal. The calorie calculator does all three steps. The rest of this guide shows how, with two worked examples, so you can see where the number comes from and how much to trust it.

Start with the federal estimates

The Dietary Guidelines table gives calories to maintain weight. It was built for a reference man who is 5 ft 10 in and 154 lb and a reference woman who is 5 ft 4 in and 126 lb, so if you are bigger or smaller than that your needs shift. Here is a slice of Table A2-2 for adults:

Age	Women, sedentary	Women, moderately active	Women, active	Men, sedentary	Men, moderately active	Men, active
21-25	2,000	2,200	2,400	2,400	2,800	3,000
31-35	1,800	2,000	2,200	2,400	2,600	3,000
41-45	1,800	2,000	2,200	2,200	2,600	2,800
51-55	1,600	1,800	2,200	2,200	2,400	2,800
61-65	1,600	1,800	2,000	2,000	2,400	2,600
71-75	1,600	1,800	2,000	2,000	2,200	2,600

The activity levels have plain definitions:

• Sedentary: only the activity of everyday living.
• Moderately active: everyday living plus the equivalent of walking about 1.5 to 3 miles a day at 3 to 4 mph.
• Active: everyday living plus the equivalent of walking more than 3 miles a day at 3 to 4 mph.

The guidelines note that calorie needs generally fall as adults age, because basal metabolic rate drops. The newer Dietary Guidelines for Americans 2025-2030, released in January 2026, make the same point in one line: the calories you need depend on your age, sex, height, weight and level of physical activity.

Get closer with a formula

A table can’t know your height and weight. A formula can. Most calculators, ours included, use the Mifflin-St Jeor equation for resting calories (basal metabolic rate, or BMR):

• Women: 10 × weight in kg + 6.25 × height in cm − 5 × age − 161
• Men: 10 × weight in kg + 6.25 × height in cm − 5 × age + 5

Mifflin and colleagues built it in 1990 from 498 healthy adults, aged 19 to 78, whose resting energy was measured in a lab. A 2005 systematic review later found it predicted resting calories within 10% of the measured value for more people than the other common equations. The BMR calculator shows it next to two other formulas.

Resting calories are only part of the day. Multiply BMR by an activity factor to get your total daily energy expenditure (TDEE), which is your maintenance number. The TDEE calculator uses five common factors, from 1.2 for a desk job with little exercise to 1.9 for a physical job plus hard training. Those five factors are a long-standing convention rather than the result of one study, so if you are torn between two levels, pick the lower one and let your weight trend tell you whether to move up.

Worked example 1: a 42-year-old woman, 5 ft 6 in, 160 lb

She works at a desk and exercises one to three days a week (“lightly active,” factor 1.375).

1. Convert units. 160 lb is 72.57 kg. 5 ft 6 in is 167.64 cm.
2. BMR. 10 × 72.57 + 6.25 × 167.64 − 5 × 42 − 161 = 725.7 + 1,047.8 − 210 − 161 = 1,402 calories.
3. Maintenance. 1,402 × 1.375 = 1,928 calories a day.

That sits between the table’s 1,800 (sedentary) and 2,000 (moderately active) for women aged 41 to 45, which is a good sign the two methods agree.

If she wants to lose weight, about 500 calories a day under maintenance gives roughly 1 lb a week, so 1,428 calories. A faster 1.5 lb a week would mean 1,178 calories, which is under 1,200. The calculator won’t show that: it shows 1,200 instead and tells her the loss will be slower. More on that floor below.

Worked example 2: a 28-year-old man, 5 ft 10 in, 190 lb

He trains three to five days a week (“moderately active,” factor 1.55).

1. Convert units. 190 lb is 86.18 kg. 5 ft 10 in is 177.8 cm.
2. BMR. 10 × 86.18 + 6.25 × 177.8 − 5 × 28 + 5 = 861.8 + 1,111.3 − 140 + 5 = 1,838 calories.
3. Maintenance. 1,838 × 1.55 = 2,849 calories a day.

The table gives 2,600 (moderately active) to 3,000 (active) for men aged 26 to 30. He is 36 lb heavier than the reference man, so landing above the moderately active figure makes sense. To lose about 1 lb a week he would eat around 2,349 calories. To gain about half a pound a week, around 3,099.

Setting a goal safely

• Rate. The CDC says people who lose weight gradually, about 1 to 2 lb a week, are more likely to keep it off than people who lose it faster.
• Floor. The 2013 AHA/ACC/TOS obesity guideline describes weight-loss diets of usually 1,200 to 1,500 calories a day for women and 1,500 to 1,800 for men. Our calculators never suggest going under 1,200 (women) or 1,500 (men). The guideline also says diets under 800 calories a day should be used only in limited cases, with medical monitoring.
• Not for everyone. These formulas are for adults. They don’t cover teens who are still growing, pregnancy or breastfeeding, or medical conditions that change your needs. In those cases, talk to your doctor or a registered dietitian.

How much to trust the number

Treat your result as an estimate, not a measurement.

• The formula can miss. The same 2005 review that favored Mifflin-St Jeor found noteworthy errors for individuals, and said older adults and US ethnic minorities were underrepresented in the studies.
• Activity is a guess. In the two examples above, moving up one activity level adds about 245 calories a day for her and 322 for him.
• Needs change as you lose. A lighter body burns less. The NIH Body Weight Planner estimates calories for reaching a goal weight and then for staying there, which helps for long-term plans.

The fix is simple: eat at your estimate for two to three weeks, weigh yourself at the same time each week, and look at the trend. If your weight isn’t doing what you expected, adjust by 100 to 200 calories and check again.

Common mistakes

• Eating your BMR. BMR is what you burn lying still. Eating only that on an active day is a bigger cut than it looks.
• Using a single “2,000 calories” figure. The Dietary Guidelines use a 2,000-calorie pattern as a reference for serving goals. Your own needs can be hundreds of calories either side.
• Counting exercise twice. If you picked an active level, the workouts are already in your number. Don’t add tracker calories on top.
• Never re-checking. Re-run the numbers after every 10 lb or so of change.

Next steps

Once you have a daily target, the calorie deficit calculator turns a weight goal into a date, and the macro calculator splits your calories into grams of protein, carbs and fat.

This guide explains published estimates and is not medical advice. If you have a health condition, are pregnant or breastfeeding, or are under 18, talk to your doctor or a registered dietitian before changing how much you eat.