Calorie Calculator
Estimate how many calories you burn each day and how many to eat to lose, maintain, or gain weight. Based on the Mifflin-St Jeor equation - the same method registered dietitians use as a starting point.
Your details
Enter your age, height, and weight to see your results.
This calculator gives an estimate. Treat it as a starting point and verify it against real-world results over two weeks.
How this calorie calculator works
The calculator runs a two-step estimate that nutrition professionals use as a default starting point. First it predicts your BMR (basal metabolic rate) - the energy your body burns at complete rest - using the Mifflin-St Jeor equation, published in 1990 and currently the most accurate widely-available BMR formula for non-obese 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
Then it multiplies your BMR by an activity factor to get your TDEE (total daily energy expenditure) - the number of calories you actually burn in a day. That TDEE is your maintenance: eat that much and your weight holds steady. Your goal adjusts it - a 500 kcal deficit for roughly a pound of loss per week, or a surplus for gain.
Want the full walkthrough, including how to verify your number with a two-week test? Read our maintenance kcal guide.
Activity levels explained
| Level | Multiplier | What it means |
|---|---|---|
| Sedentary | ×1.2 | Desk job, little or no exercise |
| Lightly active | ×1.375 | Light exercise 1-3 days/week |
| Moderately active | ×1.55 | Moderate exercise 3-5 days/week |
| Very active | ×1.725 | Hard exercise 6-7 days/week |
| Extra active | ×1.9 | Physical job or 2x daily training |
Most desk workers overestimate this. If you sit for work and train a few times a week, pick lightly active - not moderately active.
How to use your results
Pick a target, then verify it. Use the calculator's daily target for two weeks while tracking your weight each morning. If your weekly average moves in the direction you want, your estimate is close enough. If not, adjust by 100-200 kcal and repeat.
Don't chase a big deficit. A 500 kcal deficit is the classic "one pound per week" pace, but a 250 kcal deficit is far easier to sustain and still adds up. The diet you stick with beats the diet you quit.
Floor matters. Most adults should not eat below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision. If your target falls below that, choose a gentler pace.
Track to stay honest. A target only works if you log what you actually eat. That's where TellMeal comes in - log meals in seconds and see your progress against your daily target.
Frequently asked questions
How accurate is this calorie calculator?
The Mifflin-St Jeor equation is within about 10% for most non-obese adults, but it can be off more for people who are very lean, very muscular, or at the extremes of age. Treat the number as an estimate and verify it with a two-week eat-and-weigh test before trusting it.
What formula does the calculator use?
Mifflin-St Jeor, published in 1990. It predicts BMR from weight, height, age, and sex, then multiplies by an activity factor to estimate total daily energy expenditure (TDEE). It is the default BMR estimate used by most modern nutrition tools.
How many calories should I eat to lose weight?
Start with your maintenance (TDEE) and subtract 250-500 kcal. A 500 kcal deficit usually produces roughly one pound of loss per week. Go no lower than 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision.
What's the difference between BMR and TDEE?
BMR is the energy you would burn lying in bed all day doing nothing - just keeping your organs running. TDEE is BMR plus everything else: activity, digestion, and daily movement. TDEE is the number you eat against to lose, maintain, or gain weight.
Should I use metric or imperial units?
Either works - the calculator converts internally before applying the formula, so the result is identical. Use whichever you think in. US food labels show "Calories" (which equal kcal), so the unit you enter does not change the output.
Is a 1,200 calorie diet safe?
For many people, 1,200 kcal/day is too low to meet nutritional needs and is hard to sustain. It should generally not be a long-term target without medical supervision. If your calculated target is near this floor, pick a gentler deficit or increase activity instead.
Put your number to work
Now that you know your target, track what you eat against it. TellMeal logs meals in seconds and shows your progress - no barcode scanning, no clutter.
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