Calorie Intake Calculator
Your daily calorie needs depend on your age, height, weight, gender, and how active you are. This calorie calculator works them out using the Mifflin-St Jeor formula, the same equation dietitians trust, and shows how many calories you need to maintain your weight, lose it, or gain it. A moderately active 25-year-old man at 5’10” and 160 lb, for example, burns about 2,660 calories a day. To lose about a pound a week he would eat around 2,160.
Below you will find how the calculation works, how many calories are in a pound, how to set a calorie deficit or surplus, and daily calorie charts by activity level.
How Many Calories Should You Eat a Day?
Most adults need somewhere between 1,600 and 3,000 calories a day, but your exact number is personal. It comes down to your Basal Metabolic Rate (the energy you burn at rest) multiplied by how active you are. The calculator above does this instantly, then adjusts for your goal.
As a rough guide, moderately active women often need around 1,800 to 2,200 calories a day to maintain weight, and moderately active men around 2,400 to 2,800. Age, muscle mass, and activity shift these up or down. The only way to get your real number is to calculate it from your own stats, which is exactly what this tool does.
How Are Daily Calories Calculated?
Your daily calorie need is built in two steps: find your BMR, then multiply by an activity factor to get your total daily energy expenditure (TDEE).
Step 1: Basal Metabolic Rate (BMR)
BMR is the calories your body burns just to stay alive: breathing, circulation, keeping warm. It is the biggest chunk of your daily burn. This calculator uses the Mifflin-St Jeor equation, the most accurate common formula:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
A 30-year-old man at 80 kg and 180 cm has a BMR of about 1,780 calories. That is what he would burn lying in bed all day.
Step 2: Activity Level (TDEE)
Almost nobody stays in bed all day, so you multiply BMR by an activity factor to get your true daily burn, your TDEE:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise | × 1.2 |
| Lightly active | Exercise 1 to 3 days/week | × 1.375 |
| Moderately active | Exercise 3 to 5 days/week | × 1.55 |
| Very active | Exercise 6 to 7 days/week | × 1.725 |
| Extra active | Hard exercise or physical job | × 1.9 |
That 1,780 BMR at a moderate activity level (1.55) becomes a TDEE of about 2,760 calories. That is his maintenance level, the amount that keeps his weight steady.
How Many Calories Are in a Pound?
One pound of body fat holds roughly 3,500 calories. This single number is the foundation of nearly every weight loss and weight gain plan, so it is worth understanding.
Because a pound equals about 3,500 calories, the math for changing your weight is simple:
- To lose one pound, you need a total deficit of about 3,500 calories
- To gain one pound, you need a surplus of about 3,500 calories
Spread over a week, that means a daily deficit or surplus of 500 calories changes your weight by about one pound in seven days.
Calories to Pounds Chart
| Daily Deficit | Weekly Deficit | Weight Change per Week |
|---|---|---|
| 250 calories | 1,750 calories | About 0.5 lb lost |
| 500 calories | 3,500 calories | About 1 lb lost |
| 750 calories | 5,250 calories | About 1.5 lb lost |
| 1,000 calories | 7,000 calories | About 2 lb lost |
The same works in reverse for gaining weight. A 500-calorie daily surplus adds about a pound a week. Keep in mind the 3,500 figure is an estimate; real results vary with water, muscle, and metabolism, but it is close enough to plan by.
Calorie Deficit: How to Lose Weight
To lose weight you eat fewer calories than you burn. That gap is called a calorie deficit, and it is the only thing that actually drives fat loss. No food or trick works without it.
A safe, sustainable deficit is 250 to 500 calories below your maintenance for steady loss, or up to 1,000 for faster loss. Going lower than that risks muscle loss, low energy, and rebound eating. Here is what different deficits look like for a person maintaining at 2,500 calories:
- Mild loss (0.5 lb/week): eat about 2,250 calories
- Standard loss (1 lb/week): eat about 2,000 calories
- Faster loss (2 lb/week): eat about 1,500 calories
Do not drop below about 1,500 calories for men or 1,200 for women without medical supervision. Protecting muscle while you lose fat matters just as much as the deficit itself, which is where enough protein comes in.
Calorie Surplus: How to Gain Weight
To gain weight, especially muscle, you flip the equation and eat more than you burn. This is a calorie surplus. A modest surplus of 250 to 500 calories above maintenance supports lean gains without piling on excess fat.
Bigger surpluses add weight faster but more of it is fat. For most people chasing muscle, a slow 250 to 500 calorie surplus paired with strength training is the sweet spot. That is roughly 0.5 to 1 pound of gain per week. If you are underweight or struggling to grow, a larger surplus can help you catch up. Pair the extra calories with training and adequate protein so the weight you add is mostly muscle, not just fat.
What Are Maintenance Calories?
Your maintenance calories are the amount that keeps your weight exactly where it is, no gain, no loss. It is simply your TDEE. Knowing this number is the starting point for any goal, because you build a deficit or surplus from it.
Here are rough maintenance levels for common profiles, calculated with this tool:
| Person | Activity | Maintenance Calories |
|---|---|---|
| Woman, 25, 5’4″, 130 lb | Sedentary | About 1,580 |
| Woman, 30, 5’5″, 150 lb | Moderate | About 2,170 |
| Man, 25, 5’10”, 170 lb | Sedentary | About 2,120 |
| Man, 30, 6’0″, 180 lb | Moderate | About 2,810 |
These are estimates. Your real maintenance can differ by a few hundred calories, so use them as a starting point and adjust based on how your weight actually responds over two to three weeks.
What Are Net Calories?
Net calories are the calories you eat minus the calories you burn through exercise. If you eat 2,200 calories and burn 400 in a workout, your net intake is 1,800. Some people track this way to account for exercise, though most calorie targets already build activity into the TDEE, so be careful not to double-count. If your calorie goal came from a TDEE that includes exercise, you do not also subtract your workout again.
How Many Calories Do You Burn in a Day?
Your daily burn is your TDEE, and it has three parts: your BMR (around 60 to 70 percent of the total), the calories used digesting food (about 10 percent), and the calories from all movement, both exercise and everyday activity. For most people, BMR is by far the biggest piece, which is why two people of very different sizes can burn very different amounts even doing the same workout. The calculator estimates your full daily burn from your stats and activity level.
Calories and Macros: Where Do They Fit?
Calories tell you how much to eat; macros tell you what those calories are made of. Once you know your calorie target, you can split it into protein, carbs, and fat to match your goal.
- Protein: 4 calories per gram, protects muscle and keeps you full. Set it with a protein calculator.
- Carbs: 4 calories per gram, your main energy source. Fine-tune with a carb calculator.
- Fat: 9 calories per gram, needed for hormones and vitamins. Check your target with a fat intake calculator.
Getting your calories right is step one. Splitting them into the right macros is step two, and it is what turns weight loss into fat loss while keeping your energy steady.
Tips to Hit Your Calorie Target
- Track honestly for two weeks to learn portion sizes, then loosen up
- Prioritize protein at every meal to stay full on fewer calories
- Fill up on vegetables, which add volume for very few calories
- Watch liquid calories, since drinks add up fast without filling you
- Adjust every few weeks based on real results, not daily scale swings
Consistency beats perfection. Hitting your target most days, most weeks, is what produces results over time.
Frequently Asked Questions
How many calories should I eat to lose weight?
Eat 250 to 500 calories below your maintenance level for steady loss of about 0.5 to 1 pound a week. Find your maintenance with the calculator, then subtract. Avoid going below 1,500 calories for men or 1,200 for women without medical advice.
How many calories are in a pound?
About 3,500 calories. That is why a 500-calorie daily deficit leads to roughly one pound of fat loss per week (500 × 7 = 3,500). The same amount as a surplus gains a pound.
What are maintenance calories?
The calories that keep your weight stable, equal to your total daily energy expenditure (TDEE). It is your starting point: subtract from it to lose weight, add to it to gain.
How many calories do I burn a day?
Your total daily burn (TDEE) is your BMR multiplied by an activity factor from 1.2 to 1.9. For most adults it lands between 1,800 and 3,000 calories. The calculator estimates it from your age, height, weight, gender, and activity.
How many calories should I eat to gain weight?
Eat 250 to 500 calories above maintenance for lean gains of about 0.5 to 1 pound a week. Pair the surplus with strength training and enough protein so most of the gain is muscle.