Find your daily calorie target for losing, maintaining or gaining weight, plus a macro split.
Calculated locally — your details stay in your browser.
How are daily calorie needs calculated?
BMR (Mifflin-St Jeor) = 10·kg + 6.25·cm − 5·age + 5 (men) or − 161 (women); maintenance = BMR × an activity factor of 1.2–1.9; and your target = maintenance ± a goal adjustment. A roughly 500 kcal daily deficit equals about 0.45 kg per week. A 30-year-old man, 80 kg and 180 cm, moderately active, has a maintenance near 2,760 kcal.
Understanding your result
A roughly 500 kcal daily deficit equals about 0.45 kg (1 lb) of weight change per week. Treat the macro split as a balanced starting point you can adjust.
Formula and method
BMR (Mifflin-St Jeor) = 10·kg + 6.25·cm − 5·age + 5 (men) or − 161 (women). Maintenance = BMR × activity factor (1.2–1.9). Target = maintenance ± your goal adjustment.
Assumptions and limitations
These figures are general estimates from the Mifflin-St Jeor equation and activity factors, not medical or dietary advice, and real needs vary by individual. The macro split is a balanced starting point, not a prescription. Adjust based on results, and consult a qualified professional before making significant changes, especially with a health condition.
Worked example
A 30-year-old man, 80 kg and 180 cm, moderately active and aiming to lose weight, has a maintenance of about 2,760 kcal and a target near 2,260 kcal/day.
How to use this tool
- Enter your gender, age, weight and height.
- Pick your activity level and goal.
- Press Calculate for your daily target and macros.
Common mistakes to avoid
- Over-estimating your activity level, which inflates the target.
- Setting a deficit so large that the target drops below a safe minimum.
About the Calorie Calculator
The Calorie Calculator estimates how many calories you burn each day and sets a target for your goal using the Mifflin-St Jeor equation, then suggests a balanced macro split.
Who should use this tool
People planning their eating who want a daily calorie estimate for losing, maintaining or gaining weight, plus a starting macro split. Suited to anyone comfortable using a general population formula from height, weight, age, sex and activity as a reference point they can adjust over time.
Benefits
- Estimates maintenance calories and a goal-adjusted target
- Suggests a balanced macronutrient split to start from
- Uses the widely regarded Mifflin-St Jeor equation
- Nothing is uploaded, logged or shared
Practical use cases
- Setting a starting calorie target for a goal
- Getting a balanced macro split to begin with
- Comparing targets for losing, maintaining or gaining
- Reviewing your figure as your weight changes
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Frequently asked questions
Is the Mifflin-St Jeor equation accurate?
It’s one of the most accurate predictive equations for most people, but individual metabolism varies, so adjust to your real-world results.
How does the activity factor change my target?
The tool multiplies your resting energy use by an activity factor between roughly 1.2 and 1.9 to estimate maintenance calories. A more active lifestyle raises the multiplier and the maintenance figure, while a sedentary one lowers it. Choosing the factor that best matches your typical week gives a more realistic starting target.
Should I recalculate as my weight changes?
Yes, it helps. Your resting energy use depends partly on your weight, so a noticeable change shifts the estimate. Recalculating every so often keeps your target aligned with your current body and goal. Remember the figures are general estimates, so adjust in response to your real progress rather than following them rigidly.