The average adult woman needs 1,600–2,400 calories per day, and the average adult man needs 2,000–3,000 calories per day. Your exact number depends on age, height, weight, activity level, and whether you're trying to lose, maintain, or gain weight.
This guide gives you the formula, calorie tables by age and activity level, and practical targets for losing or gaining weight.
Quick Answer by Sex and Activity
| Activity Level | Women (cal/day) | Men (cal/day) |
|---|---|---|
| 🛋️ Sedentary (little/no exercise) | 1,800 – 2,000 | 2,200 – 2,400 |
| 🚶 Light (1–3 days/week) | 2,000 – 2,200 | 2,400 – 2,600 |
| 🏃 Moderate (3–5 days/week) | 2,200 – 2,400 | 2,600 – 2,800 |
| 💪 Active (6–7 days/week) | 2,400 – 2,600 | 2,800 – 3,000 |
| 🔥 Very active (hard daily exercise) | 2,600 – 2,800 | 3,000 – 3,200 |
These ranges are based on adult averages for a moderate weight and height. Your specific number could be 200+ calories higher or lower.
How Calories Actually Work
A calorie is a unit of energy. Your body burns calories through:
- BMR (Basal Metabolic Rate): 60–70% of daily calories — the energy your body uses at rest to stay alive (breathing, circulation, cell repair).
- Physical activity: 20–30% — exercise plus daily movement (walking, chores, fidgeting).
- TEF (Thermic Effect of Food): 8–10% — the energy used to digest and absorb what you eat.
These three combined give your TDEE (Total Daily Energy Expenditure) — the number of calories you burn per day. Eating at your TDEE maintains weight. Eating less loses weight. Eating more gains weight.
The Formula to Calculate Your Calories
The most accurate formula for most adults is the Mifflin-St Jeor equation:
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Worked Example: A 30-Year-Old Woman
A 30-year-old woman weighs 65 kg, is 165 cm tall, and exercises 3–5 times per week.
To lose 1 lb per week, she'd eat about 1,624 cal/day. To gain 1 lb per week, about 2,624 cal/day.
Calorie Needs by Age
Calorie needs decline with age because muscle mass decreases and metabolism slows. Here are typical maintenance calories for a moderately active adult:
| Age | Women (cal/day) | Men (cal/day) |
|---|---|---|
| 19–30 | 2,000 – 2,400 | 2,400 – 3,000 |
| 31–50 | 1,800 – 2,200 | 2,200 – 2,800 |
| 51–60 | 1,600 – 2,000 | 2,000 – 2,600 |
| 61–70 | 1,500 – 1,900 | 1,800 – 2,400 |
| 71+ | 1,400 – 1,800 | 1,600 – 2,200 |
Rule of thumb: Calorie needs drop about 100–150 per decade after age 20. Regular strength training can slow this decline significantly.
Calorie Targets for Weight Loss
1 pound (0.45 kg) of fat equals approximately 3,500 calories. That means:
- To lose 1 lb per week → eat 500 cal/day below your TDEE
- To lose 0.5 lb per week → eat 250 cal/day below your TDEE
- To lose 2 lb per week → eat 1,000 cal/day below your TDEE (aggressive)
Minimum calorie thresholds: Women should not eat below 1,200 calories/day, men should not eat below 1,500 calories/day without medical supervision. Going lower risks muscle loss, nutrient deficiencies, and metabolic slowdown.
Calorie Targets for Weight Gain
To gain weight, eat above your TDEE:
- To gain 0.5 lb per week → eat 250 cal/day above your TDEE
- To gain 1 lb per week → eat 500 cal/day above your TDEE
- To build muscle → prioritize protein (0.7–1 g per pound of body weight per day)
Calorie Myths Busted
Myth 1: "All calories are equal"
Not quite. 100 calories of almonds triggers different hormonal responses, digestion speed, and satiety than 100 calories of candy. Protein, fiber, and healthy fats keep you fuller longer than refined carbs and sugar.
Myth 2: "You must eat breakfast"
Total daily calories matter more than when you eat. If skipping breakfast helps you eat less overall, it's fine. If it makes you binge at lunch, don't skip.
Myth 3: "Eating at night causes weight gain"
Your body doesn't have a "fat storage hour." Total calories and activity matter more than timing. That said, late-night eating often leads to extra calories from snacking.
Myth 4: "You can out-train a bad diet"
A 30-minute jog burns roughly 300 calories — the same as one donut. Exercise is for health and body composition, but weight loss is driven mainly by diet.
How to Track Your Calories
- Calculate your TDEE using the formula above or our free calculator.
- Set your target based on whether you want to lose, maintain, or gain.
- Log what you eat for 1–2 weeks using a food app (MyFitnessPal, Cronometer, etc.).
- Weigh yourself weekly under the same conditions (morning, empty stomach).
- Adjust by 100–200 calories if the scale hasn't moved in 2 weeks.
Precision vs. consistency: You don't need to hit your target exactly. Hitting within 50–100 calories most days is enough. What matters more is being consistent over weeks, not perfect every day.
Why Your Calculator Number Might Be Wrong
Online calculators estimate your TDEE using population averages. Your actual metabolism can differ by 5–10%. Reasons include:
- Muscle mass: More muscle = more calories burned. Two people the same weight can have 300+ calorie differences in TDEE.
- Genetics: Some people naturally burn more at rest.
- NEAT (Non-Exercise Activity Thermogenesis): Small movements like fidgeting add up — some people burn 500+ calories per day this way.
- Hormones: Thyroid conditions can shift metabolism significantly.
- Sleep: Chronic sleep deprivation slows metabolism and increases hunger hormones.
Skip the Math — Use a Calculator
Our free calorie calculator does all of this for you. Enter your age, sex, height, weight, and activity level — get your BMR, TDEE, daily calorie target, and a full macro breakdown.
🔥 Free Calorie Calculator
Get your daily calorie target, BMR, TDEE, and macros instantly.
Open Calorie Calculator →Related: Check Your BMI
Before setting a calorie target, check your BMI. Our free BMI calculator shows your current category, healthy weight range, and BMI Prime.
Frequently Asked Questions
How many calories should I eat a day?
The average adult woman needs 1,600–2,400 calories per day; the average adult man needs 2,000–3,000 calories per day. Exact needs depend on age, height, weight, and activity level.
How many calories should I eat to lose weight?
To lose about 1 pound (0.45 kg) per week, eat 500 calories less than your maintenance calories (TDEE). For 0.5 lb per week, cut 250 calories. Never eat below 1,200 calories/day without medical supervision.
How many calories does the average person burn a day?
The average adult burns 1,800–2,800 calories per day, depending on size, age, and activity level. Athletes and very active people can burn 3,000–4,000 calories. Sedentary people may burn as few as 1,500.
Is 1,200 calories a day enough?
1,200 calories is the minimum recommended for most adult women and is too low for most men. Eating below 1,200 calories long-term can cause muscle loss, nutrient deficiencies, and metabolic slowdown. Speak to a doctor before going below 1,200.
How many calories should I eat to gain weight?
To gain 1 pound per week, eat 500 calories more than your TDEE. To gain 0.5 pounds per week, add 250 calories. Focus on protein (0.7–1 g per pound of body weight) to build muscle rather than fat.
Do calorie needs change with age?
Yes. Calorie needs decline with age because muscle mass decreases and metabolism slows. Adults typically need about 100–150 fewer calories per decade after age 20. Older adults may need 200–400 fewer calories than younger adults.
Does metabolism slow down with age?
Yes, but slower than most people think. Muscle loss is the main driver — the more muscle you retain, the closer your metabolism stays to its younger baseline. Strength training can help preserve it.
Is 2,000 calories a day enough?
For many adults, yes — 2,000 is used as a standard reference on food labels. But it's just an average. Active men typically need more; sedentary older women typically need less.