About the Calorie Calculator
Your body uses energy even at rest — to breathe, circulate blood and keep warm. That is your basal metabolic rate (BMR). Everyday movement and exercise add to it, giving your total daily energy expenditure (TDEE), also called maintenance calories. This calculator estimates both using the Mifflin–St Jeor equation, which reviews have found to be among the most accurate formulas for healthy adults, and then shows sensible daily targets for losing, keeping or gaining weight.
How to use the Calorie Calculator
- Choose metric or imperial units.
- Enter your sex, age, weight and height.
- Pick the activity level that honestly matches a typical week.
- Read your maintenance calories, then the target for your goal.
- Track your weight for 2–3 weeks and adjust by 100–200 kcal a day if needed.
The formula behind it
Why the result is an estimate
Equations are based on averages. Two people with the same age, height and weight can burn different amounts depending on muscle mass, genetics, sleep and health conditions. Mifflin–St Jeor predicts resting energy within about 10% for most healthy adults, so treat the number as a starting point and adjust it based on how your weight actually changes.
Losing weight safely
A deficit of roughly 500–550 kcal a day leads to about 0.5 kg (1 lb) of weight loss per week for many people. Larger deficits are harder to sustain and can cause muscle loss. Eating very little — below about 1,200 kcal a day for women or 1,500 for men — is generally not advised without medical supervision.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the energy you would burn lying at rest all day. TDEE adds the energy used for daily activity and exercise, so it is always higher.
Which activity level should I choose?
Most people overestimate their activity. If you have a desk job and exercise two or three times a week, "Lightly active" is usually the best fit.
Can I use this if I am pregnant, breastfeeding or under 18?
No. Energy needs are different in these situations. Please ask a doctor or registered dietitian instead.
Is this medical advice?
No. It is an educational estimate for healthy adults. Talk to a healthcare professional before making significant changes to your diet.
Sources
About the author: Ahmed Bilal
Ahmed Bilal is the founder of VolexTool and builds and maintains every calculator on the site. Tax rates and thresholds are taken directly from official sources such as GOV.UK, HMRC, the Canada Revenue Agency and the Australian Taxation Office, the formula is shown on every page, and each update must pass more than 600 automated checks before it goes live. Ahmed is not a tax adviser: for decisions about your own situation, speak to a qualified accountant or financial adviser.