How Many Calories Should I Eat a Day by Age?

By age, adult women should eat about 1,600 to 2,400 calories a day and men about 2,000 to 3,000. The number falls as you get older. A sedentary woman needs 2,000 kcal at age 21 to 25 and 1,600 kcal from 51 on. These are estimates for a reference person from the US Dietary Guidelines table below. Use your row as the number to eat toward, then check it against your own weight.

How many calories should I eat a day by age and activity?

Find your age and your activity level in the table. It comes from Appendix 2 of the 2020–2025 Dietary Guidelines for Americans. The 2025–2030 edition I read has no such table. It says only that your calorie need depends on age, sex, height, weight and activity, which is no help if you want one number. The estimates assume a reference man of 5 ft 10 in and 154 lb (about 178 cm and 70 kg), and the reference woman is 5 ft 4 in and 126 lb (about 163 cm and 57 kg). Your own weight will differ, and a height and weight chart shows the usual range for every inch from 4 ft 10 in to 6 ft 6 in.

Age (years)	Women, sedentary (kcal/day)	Women, moderately active (kcal/day)	Women, active (kcal/day)	Men, sedentary (kcal/day)	Men, moderately active (kcal/day)	Men, active (kcal/day)
19–20	2,000	2,200	2,400	2,600	2,800	3,000
21–25	2,000	2,200	2,400	2,400	2,800	3,000
26–30	1,800	2,000	2,400	2,400	2,600	3,000
31–35	1,800	2,000	2,200	2,400	2,600	3,000
36–40	1,800	2,000	2,200	2,400	2,600	2,800
41–45	1,800	2,000	2,200	2,200	2,600	2,800
46–50	1,800	2,000	2,200	2,200	2,400	2,800
51–55	1,600	1,800	2,200	2,200	2,400	2,800
56–60	1,600	1,800	2,200	2,200	2,400	2,600
61–65	1,600	1,800	2,000	2,000	2,400	2,600
66–70	1,600	1,800	2,000	2,000	2,200	2,600
71–75	1,600	1,800	2,000	2,000	2,200	2,600
76 and up	1,600	1,800	2,000	2,000	2,200	2,400

Sedentary means only the activity of independent living. Moderately active adds about 1.5 to 3 miles of walking a day at 3 to 4 miles an hour. Active means more than 3 miles. If you sit at a desk and walk a bit, I’d guess the first or second column. When you’re unsure, start with the lower one, because two weeks of weigh-ins will tell you when to move up.

In the UK, the NHS gives 2,000 kcal a day for an average woman and 2,500 kcal for an average man as a single guide. Where labels show kilojoules, multiply kcal by 4.184, per the FAO conversion. So 2,000 kcal is 8,368 kJ. The question without the age split is how many calories per day you need.

Why do calorie needs fall as you get older?

Resting energy drops by about 5 kcal a day for every year of age. That is the age term in the Mifflin–St Jeor equation, fitted to 498 adults aged 19 to 78 in a 1990 study. For men the equation is 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. For women it ends in − 161 instead of + 5. Thirty years of age subtract 150 kcal from the resting number, which is modest but real.

Put that next to the table. From ages 26–30 to 56–60 the table cuts a sedentary adult by 200 kcal, women from 1,800 to 1,600 and men from 2,400 to 2,200, and the age term accounts for about 150 of that 200. The two come from different equations, so they won’t match to the calorie.

The table drops in steps, with long flat stretches between them. A sedentary woman sits at 1,800 kcal from age 26 to 50 and drops to 1,600 at 51. A sedentary man is at 2,400 kcal through age 40, 2,200 through 60 and 2,000 after that. Turning 40 changes little. Women’s estimates don’t move until 51, and men’s step down at 41. The newer US medians by age for women are in how many calories should a woman eat.

A lower calorie row does not lower every nutrient need. The 2025–2030 guidelines say some older adults need the same or more protein, vitamin B12, vitamin D and calcium. They point those readers to dairy, meat, seafood, eggs, legumes and whole plant foods. If your row steps down, look at your protein first.

What does a 200-calorie gap look like on a plate?

Two hundred calories is roughly one snack. I worked out these amounts from USDA records, using the specific Atwater energy where a record has it.

Food	Amount	Energy
Egg, whole, cooked, fried	2 large, 92 g	180 kcal
Yogurt, Greek, plain, whole milk	200 g	189 kcal
Peanut butter, creamy	34 g	200 kcal
Cheese, cheddar	50 g	204 kcal
Nuts, almonds, whole, raw	35 g	204 kcal
Bananas, raw	2 medium, 236 g	210 kcal

A sedentary woman moving from the 21–25 row to the 51–55 row loses 400 kcal a day from her estimate. That is two of these portions. For almonds the sum is 583.6 kcal per 100 g × 0.35 = 204 kcal. Not much food. If your plate stays the same while your row steps down, trim by about that much. How many calories should breakfast be shows where a day’s number goes at the first meal.

How do I use my row without overthinking it?

Start at your row and let the scale decide. The Dietary Guidelines call these figures estimates and point to an online calculator for a closer one. Here’s the routine I’d follow.

1. Pick the column that matches how much you walk and move.
2. Log your food for two weeks and weigh yourself three mornings a week.
3. Compare the two-week averages. If your weight is flat, what you ate is your maintenance, whatever the table says.
4. If it drifted, move your target 100 to 200 kcal and run another two weeks.

To get a number from your own age, height, weight and activity, use the calorie calculator. It uses the newer NASEM 2023 equations rather than the older ones behind this table, and it never sets a goal under its safe minimum. To lose weight from your row, how many calories should I eat to lose weight says how far below it to go.

Some people sit outside the table. This article is for adults, and the table has separate rows for children and teenagers. Pregnancy changes the numbers, and the guidelines tell women to follow their healthcare provider’s advice on calories. If you’re ill, ask your doctor.

When you’re ready to turn a row into a daily goal, Calsa asks a few questions to set one. A goal below its safe calorie floor isn’t saved, and it tells you why.