Calorie Calculator
Estimate your resting metabolic rate and daily maintenance calories using the trusted Mifflin-St Jeor equation. Free, instant, private.
For reference at this activity level
| Goal framing | Approximate daily calories |
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How to use the Calorie Calculator
- Choose metric or imperial units.
- Enter your sex, age, height and weight.
- Select the activity level that best matches a typical week.
- Read your estimated BMR and daily maintenance calories, which update live as you change any field.
Why use ZillaKit's Calorie Calculator?
Your basal metabolic rate is the energy your body uses at complete rest to keep basic functions running, and it is the foundation for estimating how many calories you burn in a day. This calculator uses the Mifflin-St Jeor equation, which research has found to be one of the more accurate predictive formulas for healthy adults. It takes your sex, age, height and weight to estimate BMR, then multiplies by a standard activity factor to give your total daily energy expenditure, or maintenance calories. Both metric and imperial units are supported and every field updates the result instantly. The reference table shows a few gentle adjustments around your maintenance figure so you can see the general ballpark, framed neutrally rather than as a diet plan. Because these are population-level estimates, real energy needs vary with genetics, body composition, health conditions and daily movement, so the numbers are a starting point for understanding rather than a prescription. Everything runs privately in your browser with no upload, no signup and nothing stored.
FAQ
What is the Mifflin-St Jeor equation?
It estimates basal metabolic rate as 10 times weight in kilograms, plus 6.25 times height in centimeters, minus 5 times age in years, plus 5 for males or minus 161 for females. It is widely regarded as accurate for most healthy adults.
What is the difference between BMR and TDEE?
BMR is the energy you would burn at rest all day. TDEE, or total daily energy expenditure, is your BMR multiplied by an activity factor to account for movement and exercise, and it represents your maintenance calories.
How accurate are these numbers?
They are solid estimates but not exact. Individual metabolism varies with body composition, genetics, health and daily activity, so treat the result as a well-founded starting point and consult a professional for personalised guidance.
Is my information uploaded anywhere?
No. Everything is calculated in your browser with JavaScript. Nothing you enter is sent to a server or stored.