How many calories do you need per day?

Most adults need somewhere between 1,600 and 3,000 calories a day. That range is wide because it has to cover a 24-year-old bricklayer and a 68-year-old office worker in the same sentence. This page narrows it down: what typical daily needs look like for people like you, what actually moves the number, and how much confidence a published figure deserves.

If you'd rather have your own calculated number than a range, the calorie calculator does it in under a minute, no account needed. If you want the arithmetic behind it and a deficit set up properly, that's the full TDEE guide.

Typical daily calorie needs

These are the estimated needs published in the Dietary Guidelines for Americans, the most widely used reference figures for healthy adults at a stable weight.

Women

Men

Sedentary means daily life only, with no deliberate exercise beyond walking around. Moderately active adds roughly the equivalent of walking 2–3 miles a day on top of that. Active means considerably more.

Those figures describe maintenance: eat about that much, weigh about the same. They're averages for an adult of average height, which means a 150 cm woman and a 180 cm woman are both hiding inside the same cell of that table. Useful as a sanity check, not as a prescription.

What actually moves your number

Four things do most of the work, in roughly this order.

Body size. The big one, and it surprises people who expect metabolism to be about luck. A larger body costs more energy to maintain and more energy to move, so weight and height drive your requirement more than anything else does. It's also why the target falls as you lose weight — more on that below.

Sex. Male bodies carry more muscle on average, and muscle is metabolically expensive tissue. This shows up as a gap of roughly 400–600 kcal a day between the two tables above. It's mostly a body-composition difference rather than a sex difference as such.

Age. Requirements decline gradually through adult life, roughly 50 kcal per decade. The driver is falling muscle mass rather than a "slowing metabolism" in any mysterious sense, which is why staying strong slows the decline.

Movement. Everything from structured training to fidgeting and standing up. This is the most variable component between two otherwise identical people — and the one people misjudge most.

That last point deserves emphasis, because it's the single biggest source of error in any calorie estimate. If you sit at a desk eight hours a day and train three times a week, you are *lightly* active, not moderately active. The optimistic answer inflates your target by 200–300 kcal, which is roughly the size of a sensible deficit. Pick the wrong column and you cancel the entire plan.

Turning maintenance into a goal

Once you have a maintenance figure, the adjustment is simple arithmetic:

• To lose weight: eat below maintenance. A deficit of 300–500 kcal a day is the sustainable range for most people, producing roughly 0.3–0.5 kg of loss per week, since a kilogram of body fat stores about 7,700 kcal.
• To maintain: eat maintenance, and let the scale trend tell you whether the estimate was right.
• To gain muscle: a modest surplus of 200–300 kcal a day is plenty. Larger surpluses mostly add fat.

Two guardrails worth stating plainly. Don't set a routine target below your resting requirement — very low intakes of 1,000–1,200 kcal are hard to hit while still getting adequate protein and micronutrients, and adherence collapses. And aggressive deficits look efficient on paper but fail statistically. Adherence, not ambition, is what predicts where you are twelve months later.

Your target shrinks as you do

This one catches nearly everyone. Lose 10 kg and your daily requirement drops by roughly 100–200 kcal — less body to maintain, less mass to carry around. The plateau that arrives after a few successful months is very often not a broken metabolism but an old target meeting a new, smaller body.

Recalculate every 5 kg or so. It's a two-minute job, and it explains most "the diet stopped working" stories.

How much should you trust any of this?

Less than the precision of the numbers suggests. Every figure on this page — and every number a calculator hands you — carries an error bar of ±10% or more for an individual. Two people with identical height, weight, age and training can genuinely differ by 200–300 kcal a day. These tables are population averages, not measurements of you.

So the useful sequence is: estimate, then measure. Take a starting number, eat to it honestly for three or four weeks, and watch the weight trend.

• Losing as planned? The estimate was right. Change nothing.
• Trend flat on a planned deficit? Your true maintenance is lower than the estimate. Your logged average intake *is* your real maintenance — subtract the deficit from that number instead.
• Losing faster than planned? Your true requirement is higher. Eat a little more and keep the rate sustainable.

The catch is that this only works if the intake side is measured rather than guessed. Logging "roughly 1,800" that's really 2,200 tells you nothing about your metabolism — only about your estimating. That's the problem calorie.one is built for: describe or photograph a meal, the AI breaks it into ingredients with gram amounts, and every calorie figure comes from USDA FoodData Central rather than a guess, shown line by line so you can correct any portion before it saves. The weight trend sits on the same dashboard, because comparing the two is the only way an estimate ever becomes your actual number.

Where to go next

• Just want your number? The calorie calculator runs the Mifflin-St Jeor equation on your stats and returns a daily target. Free, no account.
• Want to do the maths yourself and set up a deficit properly? How to calculate TDEE and set up a realistic calorie deficit has the formula, worked examples, deficit sizing, and the calibration loop that corrects the estimate using your own weight data.
• Wondering how accurate calorie numbers are in the first place? How accurate are calorie counts? covers the error sources on the food side — labels, databases and cooking.

FAQ

How many calories should I eat a day?

Most adult women need roughly 1,600–2,400 kcal and most adult men roughly 2,000–3,000, with the low end applying to sedentary and older people. Body size drives the number more than anything else does, so treat any published range as a starting point and confirm it against your own weight trend.

How many calories a day to lose weight?

Maintenance minus 300–500 kcal, which produces roughly 0.3–0.5 kg of loss a week. Avoid routine targets below your resting requirement: intakes of 1,000–1,200 kcal are hard to hit while still getting adequate protein and micronutrients, and adherence collapses.

How many calories does a woman need per day?

Between about 1,600 and 2,400, depending on age and activity: 1,800–2,000 for a sedentary woman aged 19–30, 1,600 for a sedentary woman over 60, and up to 2,400 for a young active one.

How many calories does a man need per day?

Between about 2,000 and 3,000. A sedentary man aged 19–30 needs around 2,400–2,600, an active one around 3,000, and a sedentary man over 60 around 2,000–2,200.

Why did my calorie target stop working?

Because it shrank with you. Losing 10 kg drops your daily requirement by roughly 100–200 kcal, so an old target is meeting a new, smaller body. Recalculate every 5 kg or so — that accounts for most plateaus.