How Many Calories Should I Eat Per Day? (By Age, Sex & Goal)
How many calories should I eat per day is one of the most searched nutrition questions — and the honest answer is: it depends. A sedentary 25-year-old woman needs roughly 1,800–2,000 calories to maintain her weight, while an active 35-year-old man might need 2,800–3,200. The right number for you is determined by your age, sex, height, weight, and how active you are. This guide walks you through exactly how to calculate your personal daily calorie needs and how to adjust them for your specific goal.
What Is a Calorie and Why Does the Number Matter?
A calorie is a unit of energy. Every food and drink you consume delivers a certain number of calories — and your body burns a certain number of calories every day just to stay alive and move around.
When you eat the same number of calories your body burns (your maintenance calories), your weight stays stable. Eat more and you gain weight. Eat less and you lose weight. This energy balance principle is the foundation of every successful weight management approach, regardless of what diet plan is involved.
ℹ️ The energy balance equation
Calories consumed = Calories burned → Weight stays stable. Calories consumed < Calories burned → Weight loss. Calories consumed > Calories burned → Weight gain.
How to Calculate Your Daily Calorie Needs (TDEE)
Your Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day. It has two components:
- BMR (Basal Metabolic Rate): Calories burned at complete rest — breathing, circulating blood, maintaining organ function. This is 60–70% of your TDEE.
- Activity calories: Extra calories burned through daily movement, exercise, and digestion (the thermic effect of food).
The most accurate formula for estimating BMR is the Mifflin-St Jeor equation, developed in 1990 and validated across multiple large studies. Your TDEE is your BMR multiplied by an activity factor:
| Activity Level | Description | TDEE Multiplier |
|---|---|---|
| Sedentary | Desk job, little or no exercise | BMR × 1.2 |
| Lightly Active | Light exercise 1–3 days/week | BMR × 1.375 |
| Moderately Active | Moderate exercise 3–5 days/week | BMR × 1.55 |
| Very Active | Hard exercise 6–7 days/week | BMR × 1.725 |
| Extremely Active | Physical job or twice-daily training | BMR × 1.9 |
Use our free BMR Calculator to get your personalized number in under a minute.
Average Daily Calorie Needs by Age and Sex
The following table shows estimated maintenance calorie needs at moderate activity (3–5 days of exercise per week). Individual results will vary based on height, weight, and exact activity.
| Age | Women (Moderate Activity) | Men (Moderate Activity) |
|---|---|---|
| 18–25 | 1,900–2,100 cal | 2,600–2,900 cal |
| 26–35 | 1,850–2,050 cal | 2,500–2,800 cal |
| 36–45 | 1,800–2,000 cal | 2,400–2,700 cal |
| 46–55 | 1,750–1,950 cal | 2,300–2,600 cal |
| 56–65 | 1,650–1,850 cal | 2,100–2,400 cal |
| 65+ | 1,550–1,750 cal | 1,950–2,250 cal |
ℹ️ Why calorie needs decrease with age
BMR drops about 2–3% per decade after age 20, primarily due to muscle loss (sarcopenia) and hormonal changes. Resistance training slows this decline significantly by preserving lean muscle mass.
How Many Calories Should You Eat for Your Goal?
Once you know your maintenance calories (TDEE), adjusting for your goal is straightforward:
| Goal | Daily Calories | Expected Result |
|---|---|---|
| Lose weight (slow) | TDEE − 250 cal | ~0.5 lb loss per week |
| Lose weight (moderate) | TDEE − 500 cal | ~1 lb loss per week |
| Lose weight (fast) | TDEE − 750 cal | ~1.5 lbs loss per week |
| Maintain weight | TDEE | No change |
| Gain muscle (lean bulk) | TDEE + 200–300 cal | ~0.25–0.5 lb gain per week |
| Gain weight (bulk) | TDEE + 500 cal | ~1 lb gain per week |
⚠️ Avoid going below your BMR
Eating less than your BMR (usually below 1,200–1,400 calories for most adults) causes muscle loss, metabolic slowdown, nutrient deficiencies, and unsustainable hunger. A deficit of 500 calories/day is the sweet spot for most people — fast enough to see results, slow enough to preserve muscle.
How Accurate Is Calorie Counting?
Calorie targets are estimates — not exact prescriptions. Your actual TDEE can vary by 10–15% from any formula's prediction. This is normal and expected. Treat your calculated target as a starting point, then adjust based on real results:
- If you're not losing weight after 2–3 weeks at your calculated deficit, reduce by 100–200 calories
- If you're losing more than 1.5 lbs/week consistently, increase by 100–200 calories (too fast = muscle loss)
- If you're hungry all the time, prioritize higher protein and fiber within your calorie target — not lower calories
Also note: food labels can be off by up to 20% due to ingredient variation and cooking methods. A food scale is significantly more accurate than measuring cups for tracking calorie intake.
Practical Tips for Hitting Your Calorie Target
- Track before you eat, not after. Logging in advance lets you make adjustments. Logging after the fact is just record-keeping.
- Weigh food raw. Cooking changes the weight of most foods (meat loses water, pasta absorbs it).
- Don't "save" calories for the evening. Spreading intake throughout the day reduces hunger and prevents binge eating at night.
- Build in a "flex buffer." Aim for 100 calories under your target — this absorbs small tracking errors.
- Focus on protein first. Getting 0.7–1g of protein per pound of bodyweight makes staying in a deficit dramatically easier.
Put This Into Practice — Free
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Frequently Asked Questions
How many calories should I eat to lose weight?
To lose weight, eat 300–500 calories less than your TDEE (maintenance calories). This creates a sustainable deficit that produces 0.5–1 pound of fat loss per week without excessive hunger or muscle loss. Use a BMR calculator to find your TDEE, then subtract your target deficit.
How many calories does a woman need per day?
Most women need 1,600–2,400 calories per day to maintain their weight, depending on age and activity level. Women aged 19–30 at moderate activity need roughly 2,000–2,200 calories. Women 51+ at sedentary activity may need as few as 1,600 calories. Individual needs vary — calculate your personal TDEE for an accurate estimate.
How many calories does a man need per day?
Most men need 2,000–3,000 calories per day to maintain their weight. Active men aged 18–35 can need 2,800–3,200 calories, while sedentary men over 60 may only need 2,000–2,200. Use the TDEE formula: BMR × activity multiplier for your personal target.
Is 1,200 calories a day too low?
1,200 calories is below the BMR for most adults, which means eating at 1,200 calories typically puts you in an extreme deficit. For most women this is too low and causes muscle loss, fatigue, and nutrient deficiencies. For most men it is dangerously low. The minimum recommended intake is your BMR — typically 1,400–1,800 for women and 1,600–2,200 for men.
How many calories should I eat for my height and weight?
Calorie needs are determined by your height, weight, age, sex, and activity level combined — not height or weight alone. The Mifflin-St Jeor equation uses all these variables to calculate your BMR, which you then multiply by your activity factor to get your TDEE. Use a free BMR calculator with all inputs for the most accurate result.
Free Calculators
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