Health
Calorie Calculator
Daily calorie needs from your BMR (Mifflin-St Jeor) and activity level, with targets for losing or gaining weight.
Updated:
Result
Updates as you typeDaily calories to maintain your weight
2,046 kcal
- Basal metabolic rate (BMR)
- 1,320 kcal
- Activity factor (PAL)
- 1.55
- Lose weight (−500 kcal, about 0.5 kg or 1 lb a week)
- 1,546 kcal
- Lose weight slowly (−250 kcal)
- 1,796 kcal
- Gain weight (+250 kcal)
- 2,296 kcal
- Gain weight faster (+500 kcal)
- 2,546 kcal
How it's calculated
Daily energy needs are found in two steps. First the basal metabolic rate (BMR), the energy the body uses at rest, is calculated with the Mifflin-St Jeor equation, the common formula that comes closest to measured values in healthy adults. Then BMR is multiplied by a physical activity level (PAL) factor from the FAO/WHO/UNU report. To lose weight you eat below that figure; to gain, above it.
Worked example
A lightly active woman, 30 years old, 165 cm, 60 kg:
- BMR: 10 × 60 + 6.25 × 165 − 5 × 30 − 161 = 1,320.25 kcal
- Daily needs: 1,320 × 1.55 = 2,046 kcal
- To lose weight: 2,046 − 500 = 1,546 kcal (about 0.45 kg a week)
Activity level and target tables
Daily needs by activity level
| Activity level | Description | PAL | kcal a day |
|---|---|---|---|
| Activity level: Sedentary | DescriptionDesk job, no exercise, little walking | PAL1.40 | kcal a day1,848 |
| Activity level: Lightly active | DescriptionDaily walks or light exercise 1–3 days a week | PAL1.55 | kcal a day2,046 |
| Activity level: Moderately active | DescriptionExercise 3–5 days a week or a job on your feet | PAL1.70 | kcal a day2,244 |
| Activity level: Very active | DescriptionExercise 6–7 days a week or physical work | PAL1.85 | kcal a day2,442 |
| Activity level: Extremely active | DescriptionHeavy physical work plus training; athletes | PAL2.20 | kcal a day2,905 |
Calories by goal
| Daily difference | Calories a day | Weekly change |
|---|---|---|
| Daily difference: −1,000 kcal | Calories a day1,046 kcal | Weekly change−0.91 kg |
| Daily difference: −500 kcal | Calories a day1,546 kcal | Weekly change−0.45 kg |
| Daily difference: −250 kcal | Calories a day1,796 kcal | Weekly change−0.23 kg |
| Daily difference: Maintain | Calories a day2,046 kcal | Weekly change— |
| Daily difference: +250 kcal | Calories a day2,296 kcal | Weekly change+0.23 kg |
| Daily difference: +500 kcal | Calories a day2,546 kcal | Weekly change+0.45 kg |
Frequently asked questions
How are daily calorie needs calculated?
First the basal metabolic rate (BMR) from the Mifflin-St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, plus 5 for men or minus 161 for women. Then it is multiplied by an activity factor (PAL). A lightly active 30-year-old woman of 165 cm and 60 kg has a BMR of 1,320 kcal and needs about 2,046 kcal a day; a man of 180 cm and 80 kg, 1,780 and 2,759 kcal.
What is the basal metabolic rate?
The energy your body uses at complete rest for breathing, circulation and cell repair. It makes up most of what you burn in a day and falls with age and loss of muscle mass.
Where do the activity factors come from?
From the physical activity level (PAL) ranges in the FAO/WHO/UNU 2004 report on human energy requirements: sedentary or light 1.40–1.69, active 1.70–1.99, vigorous 2.00–2.40. The calculator splits those ranges into five steps, so daily needs run from 40% to 120% above BMR.
How many calories should I eat to lose weight?
About 500 kcal a day below your needs corresponds roughly to half a kilogram (one pound) a week, by the common 3,500 kcal per pound rule (Hall 2008). For the woman in the example that is 1,546 kcal. Loss slows over time, and eating below your BMR is not advised.
How accurate is this?
The Mifflin-St Jeor equation comes within about 10% of measured values for most healthy adults; muscle mass, hormones and genetics vary from person to person. Children, pregnant and breastfeeding women, athletes and people with severe obesity need other methods.
Are calories and kilocalories the same thing?
The "calorie" on food labels is a kilocalorie (kcal, 1,000 calories). Labels often show kilojoules too: 1 kcal = 4.184 kJ.
Sources
- Mifflin MD, St Jeor ST et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51(2):241-247
- FAO/WHO/UNU — Human energy requirements, Report of a Joint Expert Consultation (Rome 2004), chapter 5, table 5.3: physical activity level (PAL) categories for adults
- Hall KD. What is the required energy deficit per unit weight loss? Int J Obes 2008;32(3):573-576 (the 3,500 kcal per pound rule and its limits)
A statistical estimate for healthy adults, not medical advice. Under-18s, pregnancy, breastfeeding, illness, medication and severe obesity need individual assessment. Results are for guidance only.