DocomintCalorie Calculator
Calculate daily calorie needs from BMR and activity level, with weight loss/gain targets.
What is a Calorie Calculator?
Multiplies BMR (calories burned at rest) by an activity factor — sedentary through very active — to estimate total daily energy expenditure (TDEE), the maintenance calorie level where weight stays stable. Also shows the standard ±500 cal/day adjustment for roughly half a kilogram of weekly weight change in either direction.
How to use the Calorie Calculator
- Enter your gender, weight, height, age, and activity level
- Press Calculate
- Your maintenance calories, plus mild deficit/surplus targets, appear instantly, computed on your device
Formula
TDEE = BMR × Activity Factor (1.2 sedentary to 1.9 very active)
BMR (calories at rest) is scaled up by how much you move, giving Total Daily Energy Expenditure — the calorie level where weight stays stable.
Example
A moderately active 30-year-old man (70kg, 175cm) has a maintenance level of about 2,594 calories/day — eating 500 less (2,094) targets roughly 0.5kg/week of weight loss; eating 500 more (3,094) targets the same rate of gain.
Common mistakes
- Overestimating activity level — most people who aren't training seriously fall closer to "sedentary" or "light" than they'd guess, which inflates the maintenance estimate.
- Treating the ±500 cal/day targets as a guarantee rather than a starting point to adjust based on real weight change over a few weeks.
- Not recalculating as weight changes over time — BMR (and therefore TDEE) shifts as body weight shifts.
Frequently asked questions
How accurate are calorie calculators?
They provide a reasonable starting estimate, typically within 10-20% of an individual's actual needs — true metabolic rate varies by genetics, muscle mass, and other factors a formula can't measure. Treat the result as a starting point to adjust based on real-world weight change over a few weeks.
What activity level should I pick?
Be conservative — most people overestimate their activity level. "Sedentary" fits a desk job with little exercise; "Moderate" fits regular exercise 3-5 days a week; reserve "Very active" for daily intense training or physically demanding work.
How many calories should I eat to lose weight?
The "Mild Weight Loss" result — roughly 500 calories below maintenance — targets about 0.5kg (1lb) of loss per week, the standard rule-of-thumb deficit most nutrition guidelines recommend as a sustainable starting point.
Why do two people with the same weight get different results?
Height, age, gender, and activity level all factor into the formula alongside weight — two people at the same weight but different heights or ages can have meaningfully different BMR and TDEE figures.
Is my numbers uploaded anywhere?
No — Calorie Calculator runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.