CALCSLIP

Calorie calculator

Daily calories to keep your weight, and to lose or gain it at a steady pace.

Sex
Units
years
cm
kg

Result

Calories to keep your weight
2,155 kcal
Basal metabolic rate (at rest)
1,390 kcal
Lose 0.5 kg a week
1,605 kcal
Lose 1 kg a week
1,055 kcal
Gain 0.5 kg a week
2,705 kcal

How this was calculated

  1. Basal metabolic rate (Mifflin-St Jeor)

    10 × kg + 6.25 × cm − 5 × age − 161

    10 × 68 + 6.25 × 165 − 5 × 32 − 161 = 1,390 kcal

  2. Daily energy use

    BMR × activity factor

    1,390 kcal × 1.55 = 2,155 kcal

  3. Target for a weekly change

    Daily use ± weekly change × 7,700 kcal/kg ÷ 7

    2,155 kcal − 0.5 × 7,700 ÷ 7 = 1,605 kcal

What this calculation assumes

  • The Mifflin-St Jeor equation predicts resting energy use within about 10% for most adults. Real needs vary with body composition, health and medication.
  • 7,700 kcal per kilogram (about 3,500 per pound) is a planning figure; weight change is rarely that linear.
  • Not for pregnancy, breastfeeding, under-18s or medical conditions. Intakes below about 1,200 kcal (women) or 1,500 kcal (men) should be supervised by a professional.

From resting energy to daily needs

BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women)

Your basal metabolic rate (BMR) is the energy your body uses at complete rest. The Mifflin-St Jeor equation, published in 1990, is the estimate most dietitians use for healthy adults because it was the most accurate in comparison studies.

Daily needs, often called TDEE (total daily energy expenditure), are the BMR multiplied by an activity factor from 1.2 for a desk job with no exercise to 1.9 for heavy physical work or training twice a day.

Targets for losing or gaining weight

A kilogram of body fat stores roughly 7,700 kcal (about 3,500 per pound), so losing 0.5 kg a week needs a deficit of about 550 kcal a day. The tape shows intakes for steady loss and gain in your units.

Weight change slows over time because a lighter body uses less energy and the body adapts. Treat the figures as a starting point and adjust after a few weeks of real results.

Questions people ask

Which activity level should I pick?

Most people overestimate. If you sit at work and exercise three times a week, choose Light or Moderate rather than Active. Exercise trackers also tend to overcount calories burned.

How accurate is the estimate?

Mifflin-St Jeor predicts resting energy within about 10% for most adults. Muscle mass, hormones, medication and genetics explain the rest, which is why tracking your weight over weeks matters more than the starting number.

Is it safe to eat less than the number shown?

Large deficits are hard to sustain and can cost muscle. Very low-calorie diets should be followed only with medical supervision, and this calculator is not for pregnancy, breastfeeding or under-18s.