How to use
- Choose metric or US units and enter your sex, age, height and weight.
- Pick the activity level that best matches a typical week.
- Read your daily calories to maintain weight and the targets for losing or gaining.
Options explained
- Basal metabolic rate
- Calories your body burns at complete rest. Mifflin-St Jeor — men 10 × kg + 6.25 × cm − 5 × age + 5, women the same minus 161.
- Activity level
- Multiplies BMR by 1.2 (sedentary) up to 1.9 (very active) to estimate total daily energy expenditure.
- Goals
- A deficit of about 500 kcal a day loses roughly 0.5 kg (1 lb) a week; 250 kcal about half that.
Examples
A 30-year-old man, 175 cm and 70 kg, has a BMR of 1,649 kcal. With moderate activity he needs about 2,556 kcal a day to maintain his weight, and about 2,056 to lose 0.5 kg a week.
Daily calories by activity level
Maintenance calories from the Mifflin-St Jeor equation, rounded to the nearest kcal:
| Person | Resting (BMR) | Sedentary | Light (1–3 days a week) | Moderate (3–5 days a week) | Active (6–7 days a week) |
|---|---|---|---|---|---|
| Woman, 30, 165 cm (5 ft 5 in), 60 kg (132 lb) | 1,320 | 1,584 | 1,815 | 2,046 | 2,277 |
| Man, 30, 178 cm (5 ft 10 in), 75 kg (165 lb) | 1,718 | 2,061 | 2,362 | 2,662 | 2,963 |
| Woman, 50, 160 cm (5 ft 3 in), 70 kg (154 lb) | 1,289 | 1,547 | 1,772 | 1,998 | 2,224 |
| Man, 45, 175 cm (5 ft 9 in), 90 kg (198 lb) | 1,774 | 2,129 | 2,439 | 2,749 | 3,060 |
Calories to lose or gain weight
A deficit of about 500 kcal a day is a common target for losing roughly 0.5 kg (1 lb) a week; 250 kcal a day gives about half that. For the moderately active 30-year-old man above, that means about 2,162 kcal a day to lose 0.5 kg a week, or 2,912 kcal to gain slowly.
Most people overestimate their activity level. Start with the lower option, track your weight for two to three weeks and adjust. For health conditions, pregnancy or competitive sport, ask a doctor or dietitian.
Frequently asked questions
How accurate is this?
It is an estimate. Individual metabolism varies by around 10%. Track your weight for a few weeks and adjust your intake if it changes faster or slower than expected.
Should I eat less than the lowest target?
Very low intakes make it hard to get enough nutrients. Diets below about 1,200 kcal (women) or 1,500 kcal (men) should be supervised by a professional.
Is my data stored?
No. Everything is calculated in your browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.