How a woman's calorie needs are worked out
This version starts with the female setting. The calculator first finds your resting calories with the Mifflin-St Jeor formula. The female version subtracts 161 at the end, while the male version adds 5. The formula was built from measured data in men and women, and that gap means a woman gets about 166 fewer calories at rest than a man of the same size and age.
Then we multiply by your activity level. The result is your maintenance number: the calories that keep your weight about the same.
What moves your number most
For women, a few things shift the result more than you might think:
- Activity. For a 145 lb (66 kg), 5 ft 5 in (165 cm) woman aged 40, maintenance goes from about 1,590 calories if she sits most of the day to about 2,060 if she exercises 3 to 5 days a week.
- Age. Each year of age trims 5 calories from your resting number.
- Weight. Each 1 kg (2.2 lb) of body weight adds 10 calories at rest.
Pregnancy and breastfeeding raise calorie needs, and this calculator does not cover them. Ask your doctor or a registered dietitian for a number that fits.
Using your results
- To lose weight, pick a row below maintenance. The 0.5 lb a week row is the gentlest.
- To gain, pick a gain row and pair it with strength training.
- Recheck every 2 to 3 weeks. Real results often slow over time as your body adapts.
Want calories tied to a goal weight and date? Try the calorie deficit calculator for women. For everyone else, there is the main calorie calculator.