How Many Calories Should I Eat Per Day? (Lose, Maintain or Gain)

"How many calories should I eat?" has no single answer because it depends on your size, age, sex and activity. What it does have is a simple three-step method that works for almost everyone.

Step 1: Find your maintenance calories

Maintenance is the amount that keeps your weight stable. It is your Basal Metabolic Rate (BMR) multiplied by an activity factor. The most accurate everyday formula is Mifflin-St Jeor:

• Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
• Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

Example: a 30-year-old woman, 65 kg and 165 cm, has a BMR of 650 + 1,031 − 150 − 161 = about 1,370 kcal. If she trains three times a week (factor 1.55) her maintenance is about 2,120 kcal. Skip the maths with the calorie calculator or the TDEE calculator.

Step 2: Pick an activity level honestly

• 1.2 – desk job, little exercise
• 1.375 – light exercise 1–3 days a week
• 1.55 – moderate exercise 3–5 days a week
• 1.725 – hard exercise 6–7 days a week
• 1.9 – physical job plus daily training

Most people are one level lower than they think. If unsure, choose the lower one and adjust.

Step 3: Adjust for your goal

• Lose fat: eat 15–20% below maintenance (about 300–600 kcal). Expect 0.25–0.75 kg (0.5–1.5 lb) per week.
• Maintain: eat at maintenance.
• Build muscle: eat 5–10% above maintenance (about 150–300 kcal) and lift weights.

Why calories are not the whole story

Two 1,800 kcal days can feel very different. Protein keeps you full and protects muscle, fibre keeps digestion regular, and whole foods are harder to overeat. After your calorie target, set protein at 1.6–2.2 g per kg with the protein calculator and split the rest using the macro calculator.

How to check and adjust

Follow your target for two to three weeks and track your average weekly weight rather than daily numbers. If weight is not moving in the direction you want, change intake by about 100–200 kcal and reassess. Recalculate every 4–6 weeks or after 2–3 kg of weight change, as described in our TDEE guide.

Special cases

Calorie needs are higher during pregnancy and breastfeeding, and lower with some medical conditions. Teenagers, people with a history of eating disorders, and anyone with diabetes or thyroid disease should get personalised advice from a doctor or registered dietitian rather than relying on a calculator alone.

Bottom line

Estimate maintenance, adjust by 10–20% for your goal, track for a few weeks and tweak. The number you get is a starting point – your body's response is the real answer.