How Many Calories Should I Eat Per Day?
Key takeaways
- How many calories should I eat a day depends on your BMR (what you burn at rest) times an activity multiplier — a moderately active 35-year-old woman at 65 kg needs about 2,085 calories a day.
- BMR is your at-rest burn; TDEE (total daily energy expenditure) adds everything else — movement, exercise, digestion — and TDEE is the number that matters for eating.
- To lose roughly 0.5 kg a week, eat about 500 calories below TDEE; to gain, eat 300–500 above it.
- Generic “2,000 calories a day” advice ignores your size, age, and activity — a calculator tuned to you beats it every time.
How many calories should I eat a day? The honest answer is: it depends on your body and your life. A 65 kg office worker and a 90 kg construction worker can differ by 1,000 calories a day or more. This guide shows you how to find your number — and how to adjust it for weight loss, maintenance, or muscle gain.
If you want the answer without the math lesson, our free calorie calculator does it in under a minute. Read on if you want to understand what it’s doing and why generic advice keeps failing you.
BMR vs. TDEE: the two numbers that matter
BMR (basal metabolic rate) is the energy your body burns just keeping you alive — breathing, circulating blood, maintaining body temperature. For most people it accounts for 60–70% of daily calorie burn. The standard way to estimate it is the Mifflin-St Jeor equation, which uses your weight, height, age, and sex.
TDEE (total daily energy expenditure) is BMR plus everything else: walking around, exercising, digesting food, even fidgeting. TDEE is the number that decides whether you gain, lose, or maintain weight — eat below it and you lose, above it and you gain. Our TDEE calculator and BMR calculator run both for you.
How many calories should I eat a day? A worked example
Take a 35-year-old woman who weighs 65 kg, is 165 cm tall, and exercises moderately (3–5 workouts a week). Step one is BMR via Mifflin-St Jeor (women: 10 × weight + 6.25 × height − 5 × age − 161):
10 × 65 + 6.25 × 165 − 5 × 35 − 161 = 650 + 1,031.25 − 175 − 161 = 1,345 calories at rest.
Step two is multiplying by an activity factor to get TDEE:
| Activity level | Multiplier | Her TDEE |
|---|---|---|
| Sedentary (desk job, no exercise) | 1.2 | 1,614 |
| Lightly active (1–3 days/week) | 1.375 | 1,850 |
| Moderately active (3–5 days/week) | 1.55 | 2,085 |
| Very active (6–7 days/week) | 1.725 | 2,321 |
| Extremely active (physical job + training) | 1.9 | 2,556 |
Her maintenance intake is about 2,085 calories a day. Notice how much activity moves the number — the same woman with a desk job and no exercise maintains on 1,614. That 470-calorie gap is why “just eat 2,000” is useless advice: it overshoots her by nearly 400 calories a day, enough to gain roughly 0.4 kg a week.
How do I adjust calories for my goal?
Once you know your TDEE, the adjustment is simple arithmetic:
- To lose weight: eat about 500 calories below TDEE. That creates a 3,500-calorie weekly deficit, which works out to roughly 0.45 kg of fat loss per week — the classic “half a kilo a week” pace. Don’t go below about 1,200 (women) or 1,500 (men) without medical supervision.
- To maintain: eat at TDEE. Recheck every few weeks; as your weight changes, so does your TDEE.
- To gain muscle: eat 300–500 calories above TDEE, with strength training and plenty of protein. A smaller surplus keeps most of the gain as muscle rather than fat.
One more lever that makes a deficit livable: food choice. Five hundred calories of chicken, vegetables, and potatoes keeps you full for hours; 500 calories of pastry does not. Protein (1.6–2.2 g per kg daily) and fiber (25–35 g daily) are the two most filling nutrients per calorie, and prioritizing them is what separates a sustainable deficit from a miserable one.
Track for two to three weeks and watch the scale trend, not daily noise — water weight can swing a kilogram overnight. If the trend isn’t moving after three weeks, adjust by 200 calories and reassess.
Why your calorie needs change over time
Your TDEE is not a fixed number. Lose 10 kg and your BMR drops — a smaller body burns less at rest — which is why weight loss slows after a few months even when your diet has not changed. This is metabolic adaptation: the body also becomes more efficient, burning slightly fewer calories for the same activity when food is scarce.
The practical fix is simple but unglamorous: recalculate your TDEE every 5 kg lost or every 6–8 weeks, and shave another 100–200 calories off your target when progress stalls for three weeks. Adding strength training helps too, since preserved muscle keeps BMR higher than dieting alone would. Plateaus are normal physiology, not failure — they just mean the math needs updating.
The reverse happens when you gain: a bigger, more active body needs more fuel, so lifters in a surplus often find their TDEE climbing a few hundred calories over months. Either way, treat your calorie target as a moving estimate, not a tattoo.
Why calculators beat the “2,000 calorie” rule
The 2,000-calorie figure is a labeling convention, not a recommendation — it was chosen as a round number for nutrition labels. Real needs span roughly 1,600 to well over 3,000 calories depending on size, sex, age, and activity. A 55 kg sedentary woman and a 100 kg athlete have almost nothing in common nutritionally.
A calculator tuned to your stats gets you within a few hundred calories of your true TDEE on the first try, and two weeks of tracking closes the rest of the gap. Browse all our fitness and health calculators, and pair your calorie target with our healthy living basics guide for the nutrition and exercise side.
A final note for athletes and very active people: if you train hard most days, your TDEE may sit well above the table estimates — endurance athletes routinely maintain on 3,000+ calories. In that case the activity multipliers are a starting guess, not a ceiling. Fuel the work: chronic under-eating tanks performance, recovery, and eventually hormones. When in doubt, eat to performance and let the scale trend be the judge.
This article is for general information only and isn’t medical advice — talk to your doctor before changing your diet or exercise routine.
FAQs
How many calories should I eat a day to lose weight?
Eat about 500 calories below your TDEE — for a moderately active woman needing 2,085 calories, that’s roughly 1,585 a day, which loses about 0.45 kg per week. Track the scale trend for 2–3 weeks before adjusting. Avoid dropping below 1,200 (women) or 1,500 (men) daily without medical supervision.
What is the difference between BMR and TDEE?
BMR is what you burn at complete rest — typically 60–70% of your total. TDEE adds all activity: exercise, walking, digestion, daily movement. BMR is the foundation; TDEE is the number you actually eat against. You calculate BMR first, then multiply by an activity factor to get TDEE.
Is 2,000 calories a day right for me?
Maybe, but probably not exactly. Daily needs range from about 1,600 to over 3,000 calories depending on your weight, height, age, sex, and activity. A personalized estimate from a calorie calculator beats the one-size-fits-all 2,000 figure, which is really just a food-label convention.
How many calories should I eat to gain muscle?
Eat 300–500 calories above your TDEE, lift weights 3–5 times a week, and get 1.6–2.2 g of protein per kg of body weight daily. A modest surplus like this adds mostly muscle; a big surplus mostly adds fat. Expect 0.25–0.5 kg of scale gain per week.
Do I need to count calories forever?
No. Counting for 2–4 weeks teaches you what portions actually contain, and most people can maintain by habit afterward. Think of it as calibration, not a life sentence — recheck with a calculator whenever your weight, activity, or goal changes significantly.