Calorie Calculator
Estimate your daily calorie needs based on age, height, weight, and activity level.
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What Is a Calorie Calculator?
A calorie calculator estimates the number of kilocalories your body burns each day. It starts with your Basal Metabolic Rate (BMR) — the energy required to keep your organs running at rest — then multiplies by an activity factor to produce your Total Daily Energy Expenditure (TDEE).
This calculator uses the Mifflin-St Jeor equation, which research published in the Journal of the American Dietetic Association found to be the most accurate BMR predictor for most adults. It requires five inputs: age, sex, height, weight, and activity level.
Knowing your TDEE lets you set a daily calorie target. Eat at TDEE to maintain weight. Subtract 500 kcal/day to lose roughly 0.5 kg per week. Add 250–500 kcal/day to gain weight gradually.
How Do You Use This Calorie Calculator?
Enter your age, gender, height (cm), weight (kg), and activity level. Click Calculate to see your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
- Enter your age in years in the age field.
- Select your sex from the dropdown menu.
- Enter your height in centimetres.
- Enter your weight in kilograms.
- Choose your activity level from the five options provided.
- Click Calculate to see your BMR and TDEE.
- Review the maintenance, weight-loss, and weight-gain calorie targets.
How Does the Calorie Calculator Formula Work?
The formula used: Mifflin-St Jeor: BMR (men) = 10W + 6.25H - 5A + 5. BMR (women) = 10W + 6.25H - 5A - 161. TDEE = BMR × Activity Factor
The Mifflin-St Jeor equation calculates BMR separately for men and women:
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161
Multiply BMR by an activity factor (1.2 to 1.9) to get TDEE. A sedentary office worker uses 1.2. A manual labourer training daily uses 1.9. The result is your estimated total daily calorie burn in kcal.
What Are Some Example Calculations?
A 30-year-old male, 180 cm, 80 kg, moderately active: BMR = 1,780 kcal. TDEE = 2,759 kcal. To lose 0.5 kg/week, eat approximately 2,259 kcal/day.
Sedentary office worker
Female, 28 years, 165 cm, 62 kg. BMR = (10 × 62) + (6.25 × 165) - (5 × 28) - 161 = 1,361 kcal. TDEE = 1,361 × 1.2 = 1,633 kcal.
Maintenance intake: 1,633 kcal/day. Weight-loss target: 1,133 kcal/day.
Moderately active gym-goer
Male, 35 years, 178 cm, 85 kg. BMR = (10 × 85) + (6.25 × 178) - (5 × 35) + 5 = 1,788 kcal. TDEE = 1,788 × 1.55 = 2,771 kcal.
Maintenance intake: 2,771 kcal/day. Weight-loss target: 2,271 kcal/day.
Very active endurance athlete
Male, 25 years, 182 cm, 75 kg. BMR = (10 × 75) + (6.25 × 182) - (5 × 25) + 5 = 1,768 kcal. TDEE = 1,768 × 1.725 = 3,050 kcal.
Maintenance intake: 3,050 kcal/day. Surplus for muscle gain: 3,300–3,550 kcal/day.
When Should You Use a Calorie Calculator?
Use this calculator when starting a new diet or fitness programme. Knowing your TDEE gives you a calorie ceiling for weight loss or a calorie floor for muscle gain. Recalculate after every 5 kg of weight change because BMR shifts with body mass.
Recalculate when your activity level changes significantly — for example after starting a physical job, beginning a training plan, or recovering from an injury that limits movement.
What Do These Terms Mean?
How Do the Options Compare?
| Activity Level | Description | Multiplier | Example |
|---|---|---|---|
| Sedentary | Little or no exercise, desk job | 1.2 | Office worker, no gym |
| Lightly active | Light exercise 1–3 days/week | 1.375 | Casual walking, yoga |
| Moderately active | Moderate exercise 3–5 days/week | 1.55 | Gym 3–4 times/week |
| Very active | Hard exercise 6–7 days/week | 1.725 | Daily training, active job |
| Extra active | Very hard exercise or physical job | 1.9 | Athlete in full training |
What Are the Best Tips to Know?
- Weigh food with a digital kitchen scale for the first two weeks to calibrate portion-size awareness.
- Track calories for at least 7 consecutive days to capture weekday and weekend variation.
- Reduce by 500 kcal/day for 0.5 kg/week fat loss — avoid deficits larger than 1,000 kcal.
- Recalculate TDEE after every 5 kg change in body weight.
- Prioritise protein at 1.6–2.2 g per kg of body weight to preserve muscle during a deficit.
What Mistakes Should You Avoid?
- Selecting a higher activity level than actual daily movement, which inflates TDEE by 300–600 kcal.
- Forgetting to count liquid calories from coffee, juice, alcohol, and protein shakes.
- Using the same TDEE for months without recalculating after significant weight change.
- Setting a calorie target below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision.
- Ignoring the difference between gross exercise calories and net additional burn.
Frequently Asked Questions
What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at rest just to maintain basic functions like breathing, circulation, and cell production.
How many calories should I eat to lose weight?
A safe calorie deficit is 500 kcal per day below your TDEE, which leads to roughly 0.5 kg (1 lb) of weight loss per week. Avoid going below 1,200 kcal (women) or 1,500 kcal (men) without medical guidance.
What counts as moderate activity?
Moderate activity means exercising 3 to 5 days per week at moderate intensity, such as brisk walking, light jogging, cycling, or swimming for 30 to 60 minutes per session.
Is the Mifflin-St Jeor equation better than Harris-Benedict?
Yes for most adults. A 2005 review in the Journal of the American Dietetic Association found Mifflin-St Jeor predicted BMR within 10% for the largest number of participants. Harris-Benedict tends to overestimate by 5–15%.
How do I calculate calories for weight gain?
Add 250–500 kcal/day above your TDEE. This produces a gain of roughly 0.25–0.5 kg per week. Combine the surplus with resistance training to favour muscle gain over fat storage.
Do calorie needs change with age?
Yes. BMR drops by roughly 1–2% per decade after age 20 because of declining muscle mass. Recalculate TDEE every few years or after noticeable body composition changes.
Should I eat back exercise calories?
Eat back 50–75% of exercise calories reported by fitness trackers. Most devices overestimate calorie burn by 20–40%. Eating back the full amount often stalls weight loss.
Why does my weight stall even in a calorie deficit?
Water retention from sodium, stress hormones, or new exercise routines can mask fat loss for 1–3 weeks. Track your weekly average weight rather than single daily readings to see the true trend.
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