DigiKitDaily Calorie Calculator
Enter your age, height, weight and activity level to see an estimate of your basal metabolic rate and daily energy needs.
What is daily calorie need?
Your body burns energy even at rest: the heartbeat, breathing and keeping body temperature all count. This minimum is the basal metabolic rate (BMR). Add your movement during the day and you get the total daily energy expenditure (TDEE). The calories you need to maintain your weight are roughly equal to your TDEE.
The formula
The tool uses the Mifflin-St Jeor equation, one of the most common for adults:
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
- TDEE = BMR × activity factor
| Activity level | Factor |
|---|---|
| Sedentary (desk job, little exercise) | 1.2 |
| Lightly active (exercise 1-3 days/week) | 1.375 |
| Moderately active (3-5 days/week) | 1.55 |
| Very active (6-7 days/week) | 1.725 |
| Extremely active (physical job or two workouts a day) | 1.9 |
Worked example
Take a 30-year-old man, 70 kg, 175 cm, moderately active. BMR = 10×70 + 6.25×175 − 5×30 + 5 = 700 + 1,093.75 − 150 + 5 = 1,649 kcal (rounded). TDEE = 1,649 × 1.55 = about 2,556 kcal. That is roughly the energy level at which this person would maintain weight.
Reading the result sensibly
- Be honest about your activity level. Most people overestimate it; if unsure, pick the level below.
- The result is an average reference, not a fixed daily target. Day-to-day swings of 10-15% are normal.
- Calorie estimates from smart watches and gym machines are also approximate and can differ.
- Calories alone do not describe diet quality. Protein, fibre, vitamins and minerals matter too.
What this tool does not do
It does not give medical advice or a diet plan. For weight gain or loss, chronic conditions, pregnancy or concerns about eating habits, see a doctor or dietitian.
Frequently asked questions
How is daily calorie need calculated?
First the basal metabolic rate (BMR) is found with the Mifflin-St Jeor equation: 10×weight + 6.25×height − 5×age + 5 for men, and 161 less for women. BMR is then multiplied by an activity factor between 1.2 and 1.9. The result is roughly the energy you need to maintain your weight.
Is the result exact?
No. Equations give an average estimate for large groups. Muscle mass, genetics, sleep, illness and medication change individual needs. Treat the result as a starting point.
How many calories should I eat to lose weight?
That is a personal decision and this tool gives no diet advice. The ±250 kcal lines are only an illustration. For weight goals, very low calorie intakes or health conditions, talk to a doctor or dietitian.
Can children or pregnant women use it?
No. The tool is a general estimate for healthy adults aged 18-100. Needs differ in childhood, adolescence, pregnancy and breastfeeding.