Calorie Calculator
Estimate daily maintenance calories, then compare cautious deficit and surplus examples using metric or US units.
Calculate your estimate
What this tool tells you
This calculator estimates resting energy use and applies a broad activity multiplier to approximate maintenance calories. It also shows small deficit and surplus examples for education, not a personal diet prescription.
How the estimate works
The Mifflin–St Jeor equation estimates resting energy expenditure: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for the original male coefficient or −161 for the original female coefficient. That result is multiplied by the selected activity factor (1.2, 1.375, 1.55, 1.725, or 1.9) to estimate total daily energy expenditure. Examples then subtract 250 or 500 kcal, or add 250 kcal, from maintenance. The calculator withholds deficit figures below 1,200 kcal/day as a conservative safety guard.
Important limitations
All outputs are estimates. Equations and activity categories cannot account for individual metabolism, body composition, adaptive changes, illness, medication, pregnancy, breastfeeding, or every kind of movement. A calorie estimate is a starting point that may need adjustment from real-world trends. People with medical or nutritional concerns should seek individualized advice.
Frequently asked questions
Are maintenance calories exact?
No. They are a model-based starting estimate. Your observed weight trend over several weeks gives more personal information.
Why are some deficit figures not shown?
The tool does not display deficit examples below 1,200 kcal/day. This is a cautious calculator guard, not a personalized minimum or recommendation.
Which activity level should I choose?
Choose the description closest to a typical week, considering both work and planned exercise. If unsure, start conservatively and treat the output as a range rather than a measured value.
Can I use this during pregnancy or breastfeeding?
This simple equation does not model the changing energy needs of pregnancy or breastfeeding. Use guidance from a qualified healthcare professional.
Understand your energy estimate
See how resting energy and daily activity relate, and why the output is an estimate rather than a personal intake target.