Calorie Calculator

Calorie Calculator delivers exactly what its name promises, estimate daily calorie needs using the mifflin-st jeor equation, fast and free. Because it belongs to ToolsMonk's medical tools collection, the whole workflow happens on a single page instead of being spread across separate apps or websites.

This tool is especially useful for workflows such as finding how many calories to eat to lose, maintain, or gain weight, setting a daily calorie budget for a diet, and understanding your energy needs for your activity level. Because it runs directly in your browser, you can use it on desktop, tablet, or mobile while keeping the process fast and easy for one-off tasks as well as repeat work.

Everything about Calorie Calculator is tuned for speed to first result, with privacy-friendly processing and the rest of ToolsMonk's tools nearby when the next task comes up.

Calorie Calculator estimates how many calories you should eat each day for your goal, loss, maintenance, or gain, based on your age, sex, body stats, and activity level.

Under the hood it builds the number in stages: your resting metabolism (BMR), multiplied by an activity factor for your maintenance calories (TDEE), then adjusted by a deficit or surplus for your goal. That's why both your body stats and an honest activity level shape the result.

For weight loss, a moderate deficit of around 500 calories a day targets a sustainable half-kilo (pound) per week while protecting muscle and energy. Extreme cuts lose faster at first but are hard to maintain and often rebound, and eating well below your BMR for long isn't advisable.

Because it's an estimate, treat the target as a starting point: the common reasons it 'doesn't work' are overestimated activity and underestimated intake, so track honestly for a few weeks and adjust. It's informational, not medical advice, and your details never leave your browser. Pair it with the TDEE, BMR, and Macro calculators for the full picture.