How many calories do I need a day?

Bottom lineMost women maintain on roughly 1,800-2,200 kcal a day, but your number depends on BMR (weight, height, age) times activity, plus adjustments for pregnancy (+340 to +452 kcal), breastfeeding (+330 to +400), and the luteal phase (+100-300); avoid going below 1,200 kcal without medical supervision.

Most women need roughly 1,800-2,200 kcal per day to maintain their weight - but the honest answer is "it depends on your body and your day," and the dependence is calculable.

What sets your number

• Your BMR (basal metabolic rate) - what you burn at complete rest, driven by weight, height, and age. For most women this is 1,200-1,500 kcal and it is the biggest slice of the total.
• Activity - a desk-bound day multiplies BMR by about 1.2; hard daily training by 1.7-1.9. This produces your TDEE (total daily energy expenditure), the number that actually matters for maintaining weight.
• Goal - a deficit of 250-500 kcal below TDEE gives gradual weight loss of about 0.25-0.5 kg per week; the reverse for gaining.

The adjustments most calculators skip

• Pregnancy: roughly +0 kcal in the first trimester, +340 in the second, +452 in the third - "eating for two" overstates it substantially
• Breastfeeding: about +330-400 kcal/day for exclusive nursing
• Your cycle: metabolic rate rises about 100-300 kcal/day in the luteal phase (after ovulation), which is why premenstrual hunger is real physiology
• Menopause: needs drift down as muscle mass falls with age - the counter is strength training and protein, not ever-smaller portions

The floor that matters

Below about 1,200 kcal/day it becomes hard to meet nutrient needs, and chronic under-eating is a classic cause of irregular or missing periods. If your cycle changes while dieting, that is your hormones telling you the deficit is too deep.

Calculate yours: calorie calculator · what is TDEE