How Many Calories Should I Eat Per Day?
There is no single correct number of calories to eat per day. The right target for you depends on four things you can measure: your size, your age, your sex, and how active you are. Get those four right and the answer is remarkably predictable — this guide gives you the standard ranges, the exact formula, and the adjustment rules that make the number work in practice.
Daily Calorie Ranges by Age and Sex
The table below shows typical daily calorie needs for adults, based on the estimated requirements in the U.S. Dietary Guidelines. Use the lower end if you are sedentary (desk job, little exercise) and the upper end if you are very active (physical job, daily training).
| Age | Women (calories/day) | Men (calories/day) |
|---|---|---|
| 19–30 | 1,800–2,400 | 2,400–3,000 |
| 31–50 | 1,800–2,200 | 2,200–2,800 |
| 51–70 | 1,600–2,200 | 2,000–2,600 |
| 71+ | 1,600–2,000 | 2,000–2,400 |
These ranges are useful context, but they are estimates for an average-height person at a healthy weight. If you are notably taller or shorter, heavier or lighter, or your training volume is unusual, the formula in the next section will give you a far better number than any table.
How to Calculate Your Exact Calorie Target
Your maintenance calories are called your total daily energy expenditure (TDEE). The calculation has two steps.
Step 1 — Basal metabolic rate (BMR): the calories your body burns at complete rest, estimated with the Mifflin-St Jeor equation:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Step 2 — Multiply by activity:
| Activity level | Multiplier | Typical example |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1–3 days/week |
| Moderately active | 1.55 | Exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extremely active | 1.9 | Physical job + hard training |
The BMR Calculator and TDEE Calculator run this math for you in both metric and imperial units.
Worked example
A 35-year-old woman, 165 cm (5'5") and 70 kg (154 lbs), exercising 3–5 days per week:
BMR = (10 × 70) + (6.25 × 165) − (5 × 35) − 161 = 1,395 calories
TDEE = 1,395 × 1.55 = ≈ 2,160 calories/day to maintain her current weight
How Many Calories Should I Eat to Lose Weight?
Subtract from your maintenance number. A deficit of 500 calories per day produces roughly one pound of loss per week; 250 calories produces about half a pound. Slower deficits (200–300 calories) are easier to sustain and preserve more muscle — faster ones get the diet over sooner. Both work if you can stick to them.
Two guardrails matter more than speed:
- Do not eat below 1,200 calories (women) or 1,500 (men) without medical supervision — below these floors it becomes very hard to get enough protein and micronutrients
- Keep protein high (1.6–2.2g per kg) so the weight you lose is fat, not muscle — see what 150g of protein a day looks like
The Calorie Deficit Calculator builds the deficit and the expected timeline for you, and this guide covers the weight-loss math in more depth.
How Many Calories Should I Eat to Gain Weight or Build Muscle?
Add to your maintenance number. A surplus of 250–500 calories per day supports steady muscle gain of roughly 0.25–0.5 kg per month for most lifters while keeping fat gain reasonable. Larger surpluses mostly add fat faster, not muscle faster — muscle protein synthesis has a ceiling that extra calories cannot raise.
Calories drive the gain; protein and training direct it. Aim for 1.6–2.2g of protein per kg of body weight and a progressive lifting program. The Macro Calculator splits your surplus into daily protein, carb, and fat targets.
What About Maintaining Your Weight?
Eat at your TDEE. This sounds trivial but is where the formula-estimate caveat matters most: equations can be off by 10% in either direction for an individual. Treat your calculated maintenance as a hypothesis — weigh yourself 3–4 mornings per week, average the week, and adjust your intake by 100–200 calories if the 2–3 week trend moves more than you want.
Why Calorie Calculators Give Different Answers
If you have plugged your stats into several calculators and gotten numbers that differ by 200–400 calories, nothing is wrong. Sites use different equations (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle) and different activity assumptions. Mifflin-St Jeor is the current best predictor for most adults, and it is what we use across every TDEE Hub calculator. The differences matter far less than picking one number, eating it consistently for three weeks, and adjusting against real scale data.
Sample Daily Targets by Weight and Goal
To make the ranges concrete, here are calculated targets for a moderately active 35-year-old (170 cm / 5'7") at three body weights, using a 500-calorie deficit or a 300-calorie surplus:
| Body weight | Maintenance | Fat loss (−500) | Lean gain (+300) |
|---|---|---|---|
| 60 kg (132 lbs) | ≈ 1,940 | ≈ 1,440 | ≈ 2,240 |
| 75 kg (165 lbs) | ≈ 2,270 | ≈ 1,770 | ≈ 2,570 |
| 90 kg (198 lbs) | ≈ 2,600 | ≈ 2,100 | ≈ 2,900 |
(Values for a man; a woman of the same stats lands roughly 150–160 calories lower at every column because of the BMR equation.)
How to Know If Your Calorie Target Is Working
Whatever number you land on, run this protocol:
- Eat the target for 21 days without changing it — body weight fluctuates 1–2 kg day to day from water, so shorter trials are noise
- Weigh in 3–4 mornings per week and compare weekly averages, not single days
- Weight trending down 0.5–1% of body weight per week on a deficit? Hold. Faster? Add 150–200 calories. Flat? Subtract 150–200
- Recalculate fully after every 5–10 lb change — a target that was right at 200 lbs is too high at 180
Frequently Asked Questions
How many calories should I eat to lose weight?
Subtract 500 calories from your maintenance calories (your TDEE) for a loss of roughly 1 pound per week, or 250 calories for about half a pound per week. Most women land between 1,400 and 1,800 calories, and most men between 1,800 and 2,300. Do not go below 1,200 calories (women) or 1,500 (men) without medical supervision.
Is 2,000 calories a day right for everyone?
No. 2,000 calories is a regulatory average used on food labels, not a personal recommendation. Actual needs range from about 1,600 to 3,000+ calories per day depending on body size, age, sex, and activity level. A 5'2" sedentary woman may need 1,600 calories while a 6'2" active man may need 3,000.
How many calories should I eat to build muscle?
Eat 250–500 calories above your maintenance (TDEE) per day. This small surplus supports roughly 0.25–0.5 kg of muscle gain per month for most lifters while limiting fat gain. Pair it with 1.6–2.2g of protein per kg of body weight and progressive resistance training.
How many calories should I eat a day to maintain my weight?
Eat at your TDEE — your total daily energy expenditure. For most adults this falls between 1,600 and 3,000 calories. Because formulas are estimates, treat the calculated number as a starting point, weigh yourself weekly, and adjust by 100–200 calories if your weight trends up or down over 2–3 weeks.
What happens if I eat under 1,200 calories a day?
Diets below 1,200 calories (women) or 1,500 (men) make it very difficult to meet protein, vitamin, and mineral needs. Risks include muscle loss, fatigue, nutrient deficiencies, gallstones, and metabolic adaptation that makes further weight loss harder. Very low calorie diets should only be done under medical supervision.
How often should I recalculate my calorie target?
Recalculate after every 5–10 pounds of weight change, after any significant change in activity (new job, new training program), or roughly every 2–3 months during an active weight loss phase. A smaller body burns fewer calories, so a target set at 200 pounds will be too high at 180.