The Quick Answer
Most adult women need about 1,600 to 2,400 calories a day, and most adult men need about 2,000 to 3,000. Adult females are likely to require between 1,600 and 2,400 calories per day, and adult males from 2,200 to 3,000, depending on age, size, height, lifestyle and activity level.
The NHS uses simpler round numbers as a starting point. The recommended daily calorie intake is generally 2,000 calories a day for women and 2,500 for men.
For more reporting on stories like this, see USA Wirely’s US coverage.
These are averages, not your personal number. Your age, height, weight, and how much you move all change the answer. The rest of this guide shows you how to work out your own.
What Decides How Many Calories You Need?
Calories are just energy. Your body spends that energy in three ways. It uses it for basic functions like breathing and keeping your heart beating, for movement and exercise, and for digesting food.
Here is what changes the total.
Age
Calorie needs drop as you get older, mostly because people lose muscle over time. Teenagers and young adults need the most. After 50, most people need noticeably less to stay at the same weight.
Sex
Men usually need more calories than women of the same age and activity level. Men tend to carry more muscle, and muscle burns more energy than fat, even at rest.
Height and Weight
A taller, heavier body costs more energy to run than a smaller one. Your height and weight can affect how quickly you use energy.
Activity Level
This is the biggest one you can actually control. A person who sits all day and a person who walks 10,000 steps and lifts weights can differ by 500 calories or more.
Health and Medicines
Hormones such as thyroid hormones, some medicines like steroids, and being unwell can all change how much energy you burn. If you have a medical condition, your doctor’s advice beats any calculator.
How Many Calories Do I Need by Age and Sex?
This chart is based on the Dietary Guidelines for Americans 2020–2025 tables. The numbers are estimates for staying at your current weight, and your exact number may be different.
| Group | Not active | Moderately active | Active |
|---|---|---|---|
| Women, 19–30 | 1,800–2,000 | 2,000–2,200 | 2,400 |
| Women, 31–50 | 1,800 | 2,000 | 2,200 |
| Women, 51+ | 1,600 | 1,800 | 2,000–2,200 |
| Men, 19–30 | 2,400–2,600 | 2,600–2,800 | 3,000 |
| Men, 31–50 | 2,200–2,400 | 2,400–2,600 | 2,800–3,000 |
| Men, 51+ | 2,000–2,200 | 2,200–2,400 | 2,400–2,800 |
What “Active” Actually Means
People often rate themselves as more active than they are. “Moderately active” means light daily activity plus walking about 1.5 to 3 miles a day at 3 to 4 miles per hour. “Active” means walking more than 3 miles a day at that pace. If you have a desk job and a couple of gym sessions a week, you are probably “not active” to “moderately active” in daily terms.
Pregnant and breastfeeding women need extra calories, and these tables don’t cover them. Ask your doctor about your nutrition needs during and after pregnancy.
How to Calculate Your Own Calorie Needs
A calorie calculator does two steps behind the scenes. You can do both by hand in a couple of minutes.
Step 1: Find Your BMR
Your basal metabolic rate (BMR) is what your body burns at complete rest. The most widely used formula is Mifflin-St Jeor:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
The BMR accounts for most of a person’s energy needs.
Step 2: Multiply by Your Activity Level
This gives your TDEE (total daily energy expenditure), which is your maintenance calories.
- Barely any exercise: BMR × 1.2
- Light exercise 1–3 days a week: BMR × 1.375
- Moderate exercise 3–5 days a week: BMR × 1.55
- Hard exercise 6–7 days a week: BMR × 1.725
A Real Example
Take a 30-year-old woman who weighs 65 kg and is 165 cm tall.
- BMR: 650 + 1,031 − 150 − 161 = about 1,370 calories
- She exercises three or four times a week, so 1,370 × 1.55 = about 2,125 calories a day to stay at her current weight
Now take a 30-year-old man who weighs 80 kg and is 178 cm tall, with the same activity level.
- BMR: 800 + 1,112 − 150 + 5 = about 1,767 calories
- 1,767 × 1.55 = about 2,740 calories a day
Both land inside the ranges in the chart, which is a good sign the maths is working.
How Many Calories Do I Need to Lose Weight?
Start with your maintenance number, then eat less than it. That gap is a calorie deficit.
How Big Should the Deficit Be?
A common target is 500 calories a day below maintenance. To lose weight at the CDC-recommended pace of 1 to 2 pounds per week, the Mayo Clinic suggests cutting roughly 500 to 1,000 calories from your daily baseline.
Smaller deficits work too, and they are often easier to stick with. PureGym notes that a deficit of around 300 to 500 kcal a day is a safe, sustainable starting point for most people.
So if your maintenance is 2,100 calories, aiming for about 1,600 to 1,800 is a sensible place to begin.
Don’t Go Too Low
Crash diets backfire. Most adults shouldn’t eat below roughly 1,200 calories (women) or 1,500 (men) per day without medical supervision, because getting enough nutrients becomes nearly impossible. Very low calorie diets, typically under 800 kcal a day, should only be followed with medical supervision.
The 3,500 Rule Is Only a Rough Guide
You may have heard that cutting 3,500 calories equals one pound lost. It is a handy shortcut, but bodies don’t run like calculators. Medications, insulin resistance and hormonal problems can make weight loss harder than it looks on paper. Expect your own results to be a bit messier than the maths suggests.
Your needs also shift as you lose weight. As you lose weight, your TDEE may decrease, so the deficit you started with may no longer be enough. Recalculate every 10 pounds or so.
How Many Calories Do I Need to Gain Weight or Build Muscle?
Flip the idea around. You eat more than you burn. A general rule of thumb is a surplus of 250 to 500 calories a day.
A small surplus is better than a huge one. Eating 1,000 extra calories a day mostly adds body fat, not muscle. Pair a modest surplus with strength training and enough protein, and most of the extra weight is more likely to be muscle.
Should You Count Calories at All?
Counting is a useful tool for a few weeks, but not everyone needs it forever. A simple way to check your real maintenance level is to track what you eat for two weeks while your weight stays steady. That number gives you a general idea of how many calories you’re eating while maintaining your weight, so you have a goal to stick to.
Calories also don’t tell you everything. Counting calories doesn’t account for your intake of good fats, carbohydrates and proteins, which your body needs. 500 calories of grilled chicken and rice will keep you full much longer than 500 calories of biscuits. Pay attention to hunger and energy, not just the number on the app.
If you want a place to start, the NHS has a practical calorie counting guide and a page on daily calorie intake. Medical News Today also has a calorie calculator that does the maths for you, and LIVESTRONG explains how to work out a calorie deficit step by step.
Signs You’re Eating Too Few Calories
Your body usually tells you if the number is too low. Watch for constant tiredness, feeling cold all the time, poor sleep, dizziness, hair loss, low mood, or workouts that suddenly feel much harder. If that sounds like you, raise your calories and talk to a doctor or registered dietitian.
Conclusion
There’s no single number that fits everyone. Women usually land between 1,600 and 2,400 calories and men between 2,000 and 3,000, but your age, size, and activity decide where you fall. Use the formula above to find your maintenance level, then adjust: about 300 to 500 lower to lose weight, about 250 to 500 higher to gain.
Final Thoughts
Treat your calorie number as a starting estimate, not a rule carved in stone. Try it for two to three weeks, watch what your weight and energy do, and tweak by 100 to 200 calories if needed. Slow, steady changes almost always beat extreme ones.
If you have diabetes, a thyroid condition, an eating disorder history, or you’re pregnant, check with a healthcare professional before changing how much you eat.
So, what’s your goal right now: losing a few kilos, holding steady, or building muscle? Work out your maintenance number first and everything else gets easier.
Frequently Asked Questions
How many calories do I need a day to maintain my weight?
Use the two-step formula above: your BMR multiplied by your activity factor. As a rough guide, the NHS puts the average at 2,000 calories for women and 2,500 for men.
How many calories should I eat a day to lose weight?
Subtract about 300 to 500 calories from your maintenance level. For many people that works out to 1,500 to 2,000 calories a day. Avoid going below 1,200 (women) or 1,500 (men) unless a doctor is supervising you.
Is 1,200 calories a day enough?
For most people it is too low. It can create a very large deficit, and it makes getting enough protein, fibre, and vitamins hard. Some smaller or older women may do fine near that level, but it is best done with professional guidance.
Do men need more calories than women?
Yes, on average. Men usually have more muscle mass and larger bodies, so they burn more energy at rest and during activity.
How many calories do I need if I don’t exercise?
Sedentary adults need the lower end of the ranges, roughly 1,600 to 2,000 for women and 2,000 to 2,600 for men, depending on age and size.
How many calories do I need to build muscle?
Aim for about 250 to 500 calories above maintenance, eat enough protein, and train with weights regularly. A bigger surplus mostly adds fat.
Do calorie needs change with age?
Yes. They generally fall after your late twenties and again after 50, mainly because of muscle loss and lower activity. Strength training helps slow this down.
Are online calorie calculators accurate?
They are good estimates, not exact answers. Most land within about 10% of your true needs. Test the number for a few weeks and adjust based on your real weight changes.
Is it okay to eat different calories each day?
Yes. Your weekly average matters more than any single day. A bigger dinner on Saturday won’t undo your progress.
