Most adults need roughly 1,600–2,400 kcal a day if they are women and 2,000–3,000 kcal a day if they are men, according to the estimates in the Dietary Guidelines for Americans. The NHS gives a simpler rule of thumb: about 2,000 kcal for an average woman and 2,500 kcal for an average man. Where you fall inside that range depends on your age, height, weight and, above all, how much you move. To find your own number, estimate it with a formula, then check it against two or three weeks of real eating and your weight trend.
That number is your maintenance: the amount that keeps your weight stable. Eating less than it leads to weight loss over time, eating more leads to gain. Everything else in this guide is about getting from the general range to a figure that fits you.
How many calories a day: table by age, sex and activity
The table below shows selected rows from the official estimate of daily calorie needs for adults. The values are calculated for a reference man of about 178 cm and 70 kg and a reference woman of about 163 cm and 57 kg. If you are taller or heavier, your needs are usually higher; if you are smaller, lower.
| Age | Women, sedentary | Women, moderately active | Women, active | Men, sedentary | Men, moderately active | Men, active |
|---|---|---|---|---|---|---|
| 19–20 | 2,000 | 2,200 | 2,400 | 2,600 | 2,800 | 3,000 |
| 26–30 | 1,800 | 2,000 | 2,400 | 2,400 | 2,600 | 3,000 |
| 36–40 | 1,800 | 2,000 | 2,200 | 2,400 | 2,600 | 2,800 |
| 46–50 | 1,800 | 2,000 | 2,200 | 2,200 | 2,400 | 2,800 |
| 56–60 | 1,600 | 1,800 | 2,200 | 2,200 | 2,400 | 2,600 |
| 66–70 | 1,600 | 1,800 | 2,000 | 2,000 | 2,200 | 2,600 |
| 76 and older | 1,600 | 1,800 | 2,000 | 2,000 | 2,200 | 2,400 |
The activity levels are defined by walking. Sedentary means only the movement of everyday life. Moderately active means the equivalent of walking about 2.5–5 km a day at a brisk pace on top of daily life. Active means more than about 5 km a day at that pace. Most people with a desk job and a few workouts a week are closer to sedentary or moderately active than to active.
Two patterns stand out. Men need more than women at the same age and activity, mainly because they are on average larger. And needs fall slowly with age, because resting metabolism declines; a woman of 60 typically needs less than she did at 25 even if her weight has not changed.
How to calculate your own daily calorie needs
A table describes an average person. For a closer estimate, use your own measurements:
- Estimate your resting energy (BMR). This is what your body burns at rest. The Mifflin–St Jeor equation is a common choice: for men 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5; for women the same with −161 at the end. The BMR calculator does the arithmetic.
- Multiply by an activity factor. Typical factors are 1.2 for little or no exercise, 1.375 for light exercise one to three days a week, 1.55 for moderate exercise three to five days and 1.725 for hard exercise six to seven days. The result is your estimated maintenance. If you hesitate between two levels, take the lower one.
- Adjust for your goal. To keep your weight, eat at maintenance. To lose weight, plan a moderate deficit below it; the guide to the calorie deficit explains how large it should be. To gain, add a small surplus and keep protein high.
- Check the number against reality. Log what you eat for two to three weeks and weigh yourself a few mornings a week under the same conditions. If the weekly average is stable while you eat close to your estimate, the estimate is right. If it drifts, adjust by 100–200 kcal and test again.
Here is what the formula gives for two example people. Both are estimates, and real needs can be a few hundred calories higher or lower.
| Example | BMR | Activity factor | Estimated maintenance |
|---|---|---|---|
| Woman, 30, 165 cm, 62 kg, light exercise | about 1,340 kcal | × 1.375 | about 1,840 kcal |
| Man, 35, 178 cm, 80 kg, moderate exercise | about 1,740 kcal | × 1.55 | about 2,700 kcal |
The woman's result sits between the table's sedentary and moderately active values for her age, and the man's is higher than the table because he is heavier than the reference man. That is exactly why your own measurements matter.
Why 2,000 calories is on every food label
The percent Daily Values on nutrition labels are based on a 2,000-calorie diet. The FDA describes this figure as a general guide for nutrition advice, not a personal target. It is a convenient round number close to the needs of many adults, but for a small, inactive woman it may be too much, and for a tall, active man it may be far too little. Use the label to compare foods, and your own estimate to plan the day.
What 1,500, 2,000 or 2,500 calories look like in food
Numbers become clearer once you split them into meals. A simple way is to give breakfast and dinner about a quarter of the day each, lunch about a third, and leave the rest for one or two snacks. For 2,000 kcal that is roughly 500 kcal for breakfast, 650–700 for lunch, 500 for dinner and 300 for snacks. For 2,500 kcal, scale each meal up by about a quarter; for 1,500 kcal, down by about a quarter.
If you would rather see real food with grams, the ready menus show complete days: the 1,500 kcal meal plan, the 2,000 kcal meal plan and the 2,500 kcal meal plan, plus other calorie levels. Each lists every portion, its calories and protein, so you can compare it with what you eat now.
Calories are not the whole picture
The same number of calories can come from very different days. Once you know your target, split it into protein, carbs and fat; the macro calculator does this from your weight and goal. Enough protein and fibre make a given number of calories more filling, which matters most when you eat below maintenance.
Common mistakes when working out daily calories
- Overestimating activity. One hard workout does not make the whole week active. Count walking and daily movement, and be honest about the hours spent sitting.
- Adding exercise calories on top. If you already chose an activity factor that includes your workouts, do not add the calories from a fitness tracker again.
- Trusting the formula over the scale. Formulas describe averages. Two to three weeks of logging and weighing tell you more about your real needs than any equation.
- Judging by single days. Weight moves with water, salt and digestion. Compare weekly averages, both for food and for the scale.
- Never recalculating. Needs change when your weight, age or routine changes. Recheck after every 4–5 kg lost or gained, or when your activity changes.
When to ask a professional
The estimates in this guide are for healthy adults. Calorie needs are different during pregnancy and breastfeeding, for children and teenagers, for athletes in heavy training, and for people with medical conditions or on medicines that affect weight. In those cases, follow the advice of your doctor or a registered dietitian. If counting calories makes you anxious or you have a history of disordered eating, talk to a professional before setting a target.