How Many Calories Should I Eat Per Day? A Simple Guide by Age, Gender & Goal

The most Googled nutrition question isn't about keto, intermittent fasting, or superfoods — it's simply: how many calories should I eat?

And the answer you'll find most places — "about 2,000 calories" — is a rough population average that may have nothing to do with your body. Your actual number depends on your age, gender, activity level, and whether you're trying to lose weight, build muscle, or maintain where you are.

By the end of this guide, you'll know exactly how to calculate your personal calorie needs — and how to stay on track without overthinking it. (Spoiler: research shows calorie counting works, especially when tracking is effortless.)

What Are Calories, Really?

A calorie is simply a unit of energy. Your body uses calories for everything — breathing, circulating blood, thinking, digesting food, walking to the kitchen, and powering your workouts.

Here's the basic science: your body is constantly burning energy to keep you alive, even when you're sleeping. The total energy you burn in a day determines how many calories you need to consume. Eat more than you burn and the excess gets stored (primarily as fat). Eat less and your body taps into those stores.

It's worth noting that not all calories are equal in terms of nutrition. 200 calories from salmon and vegetables will keep you full and fueled far longer than 200 calories from candy. But when it comes to energy balance — gaining, losing, or maintaining weight — total calorie intake is what matters most.

How Many Calories Does the Average Person Need?

Health organizations provide general guidelines as a starting point:

• Women: approximately 1,600–2,400 calories per day
• Men: approximately 2,000–3,000 calories per day

But "average" is misleading because no one is truly average. Your daily calorie needs depend on four key factors: age, gender, activity level, and goal.

Here's a quick reference chart based on the USDA Dietary Guidelines for Americans:

Source: USDA Dietary Guidelines for Americans

These numbers are useful as a ballpark — but they're still generalizations. A 30-year-old woman who runs marathons has very different needs than a 30-year-old woman who works a desk job. To find your number, you need to do a quick calculation.

How to Calculate Your Personal Calorie Needs

The most reliable way to determine your daily calorie needs is a three-step process: calculate your BMR, multiply by your activity level, and adjust for your goal.

Step 1 — Calculate Your BMR (Basal Metabolic Rate)

Your BMR is the number of calories your body burns at complete rest — just to keep your organs functioning, your heart beating, and your lungs breathing. For most people, BMR accounts for 60–70% of total daily calorie burn.

The most accurate formula, backed by research, is the Mifflin-St Jeor equation:

• Men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5
• Women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161

Worked example: Let's say you're a 30-year-old woman, 5'5" (165 cm), 150 lbs (68 kg):

BMR = (10 x 68) + (6.25 x 165) - (5 x 30) - 161 BMR = 680 + 1,031 - 150 - 161 BMR = 1,400 calories/day

This means your body burns about 1,400 calories per day just by existing — before any physical activity.

Step 2 — Multiply by Your Activity Factor (TDEE)

Your BMR only covers resting energy. To find out how many calories you actually burn in a day, you need your Total Daily Energy Expenditure (TDEE). Multiply your BMR by the activity factor that best matches your lifestyle:

Continuing our example: If our 30-year-old woman exercises moderately (3–4 days per week):

TDEE = 1,400 x 1.55 TDEE = 2,170 calories/day

This is her maintenance calories — the amount she'd need to eat to stay at her current weight.

Step 3 — Adjust for Your Goal

Your TDEE tells you how much to eat to maintain your current weight. From there, adjust based on what you're trying to achieve:

• Lose weight: subtract 300–500 calories from your TDEE
• Maintain weight: eat at your TDEE
• Gain muscle: add 250–500 calories above your TDEE

For our example: To lose about one pound per week, our 30-year-old woman would eat approximately 1,670–1,870 calories per day (TDEE of 2,170 minus 300–500).

The "500-calorie rule" is based on the principle that one pound of body fat contains roughly 3,500 calories, so a 500-calorie daily deficit equals about one pound of fat loss per week. For a deeper dive into setting up your deficit, check out our calorie deficit guide.

Calorie Needs for Common Goals

How Many Calories to Lose Weight

For safe, sustainable weight loss, most experts recommend:

• Women: no fewer than 1,200 calories per day
• Men: no fewer than 1,500 calories per day

A moderate deficit of 300–500 calories below your TDEE typically produces 0.5–1 pound of fat loss per week. This pace preserves muscle mass, maintains energy levels, and is far more sustainable than crash dieting.

Why do extreme deficits backfire? When you restrict calories too aggressively, your body responds with metabolic adaptation — it slows down non-essential functions, increases hunger hormones, and becomes more efficient at storing energy. The result: your weight loss stalls, you feel terrible, and the moment you eat normally again, the weight comes back fast.

How Many Calories to Build Muscle

Building muscle requires a caloric surplus — eating 250–500 calories above your TDEE. This gives your body the extra energy it needs to repair and grow muscle tissue after resistance training.

A few key points:

• Protein matters more than total calories for muscle growth — aim for 0.7–1 gram per pound of body weight
• A moderate surplus (250–300 calories) minimizes fat gain while still supporting muscle growth
• You need a consistent resistance training program — extra calories without stimulus just become stored fat

How Many Calories to Maintain Weight

If you're happy with your current weight and body composition, simply eat at your TDEE. But "maintenance" doesn't mean you stop paying attention.

Most people gain weight gradually — an average of 1–2 pounds per year — because of calorie creep: small, unnoticed increases in portion sizes, snacking habits, or decreased activity. Periodic tracking (even for just a week every few months) helps you catch this drift before it becomes a problem.

5 Common Mistakes When Estimating Your Calorie Needs

1. Overestimating your activity level. Most people with desk jobs are "sedentary" or "lightly active" — not "moderately active." Be honest about how much you actually move throughout the day, not just your workouts. A 45-minute gym session doesn't offset 10 hours of sitting.

2. Forgetting liquid calories. A large flavored latte is 300+ calories. A glass of orange juice is 110. Two glasses of wine at dinner is 250. Smoothies can easily hit 500+. These add up fast and are easy to overlook when tracking.

3. Not adjusting as you lose weight. A smaller body burns fewer calories. If you calculated your TDEE at 180 lbs but now weigh 165 lbs, your old target may no longer create a meaningful deficit. Recalculate every 10–15 pounds.

4. Relying on the generic "2,000 calorie" label. The 2,000-calorie figure on nutrition labels is a rough population average — not a recommendation for you. Your actual needs could be 1,500 or 2,800 depending on your stats and goals.

5. Eyeballing portions instead of measuring. Research consistently shows people underestimate their calorie intake by 30–50%. That "tablespoon" of peanut butter is probably two. That "medium" bowl of pasta is probably a large. This is exactly why CalorieCue uses AI photo recognition — snap a pic and get an accurate estimate without measuring cups or food scales.

The Easiest Way to Track Your Daily Calories

Here's the uncomfortable truth about calorie counting: 80% of people who try manual food logging quit within two weeks. Not because they lack discipline — because the process is tedious. Searching databases, weighing food, estimating portions, logging every ingredient — it adds up to 30+ minutes of data entry per day.

That's not a willpower problem. It's a design problem.

This is exactly what AI-powered food logging was built to solve. With CalorieCue, tracking your calories takes about three seconds per meal:

1. Snap a photo of your food
2. Review the instant AI breakdown — calories, protein, carbs, and fat
3. Confirm and move on with your day

No database searching. No manual entry. It works with home-cooked meals, restaurant food, and packaged items. And it automatically tracks your daily totals against your personal calorie goal.

When tracking is this effortless, consistency stops being a challenge. And consistency is what actually determines whether you reach your goals. Learn more about how AI food scanning works.

Download CalorieCue

Frequently Asked Questions

How many calories should a 40-year-old woman eat per day?

A 40-year-old woman typically needs between 1,600 and 2,200 calories per day, depending on her activity level. Sedentary women fall on the lower end (1,600–1,800), while women who exercise regularly may need 2,000–2,200 or more. The reference chart above provides estimates by age group, but for a precise number, calculate your personal TDEE using the formula in Step 1 and Step 2 — or use our TDEE calculator.

Is 1,500 calories a day enough to lose weight?

For most people, yes. A 1,500-calorie diet creates a moderate deficit for the average adult and can lead to steady weight loss of about 1 pound per week. However, the right number depends on your individual TDEE — someone with a higher TDEE may lose weight on 2,000 calories, while someone smaller may need less than 1,500. The key is creating a 300–500 calorie gap below your maintenance level.

Should I eat back the calories I burn exercising?

Partially. A good rule of thumb is to eat back about 50% of your exercise calories. This prevents under-fueling while still maintaining your deficit. Fitness trackers tend to overestimate calorie burn by 20–30%, so eating back 100% often erases your deficit entirely. For example, if your watch says you burned 400 calories, eat back about 200.

How many calories should I eat while breastfeeding?

Breastfeeding typically requires an additional 300–500 calories per day above your normal maintenance level. Most breastfeeding women need at least 1,800 calories per day to maintain milk supply and energy levels. This is not the time for aggressive calorie restriction — always consult your doctor before reducing calories while breastfeeding.

Do I need to count calories forever?

No — and you shouldn't feel like you have to. Calorie counting is a tool for building awareness, not a lifelong obligation. Most people find that after a few months of consistent tracking, they develop a solid intuitive sense of portion sizes and calorie content. The goal is to reach a point where you can make smart food choices without logging every bite. CalorieCue is designed to teach you portion awareness so you can eventually transition to intuitive eating with confidence.

The Bottom Line

Your daily calorie needs are unique to you — they depend on your age, gender, height, weight, activity level, and goals. Generic advice like "eat 2,000 calories" doesn't cut it.

Here's the simple formula:

1. Calculate your BMR using the Mifflin-St Jeor equation
2. Multiply by your activity factor to find your TDEE
3. Adjust for your goal — subtract for weight loss, add for muscle gain, or maintain

The math takes five minutes. The real challenge is staying consistent with your target — and that's where most people struggle, not because they lack willpower, but because traditional tracking is too tedious.

The easiest way to hit your daily calorie goal? Make tracking effortless. Snap a photo, get your numbers, and get on with your life.

Download CalorieCue