Calorie Calculator

Calorie Calculator estimates total daily energy expenditure: the energy your body uses in a day including everything you do. It starts from the Mifflin-St Jeor basal rate and multiplies by an activity factor, which is the standard approach and the one most apps use.

The split between rest and activity is shown separately because it surprises people. For a moderately active adult, around two thirds of daily energy use is basal: the body running itself. Exercise contributes less than most estimates assume, which is why activity level is the input people most often overstate.

The adjustment field exists rather than a built-in weight loss target, deliberately. A deficit or surplus is a decision with health implications, and the appropriate size depends on circumstances no calculator knows. The page refuses to display a target below 800 calories a day, which is under any level that should be attempted without medical supervision.

This is general information and not medical advice. The formula cannot know your medical history, your medication, your body composition or anything else specific to you. Speak to a doctor or another qualified professional about any question concerning your health, and never delay seeking advice because of a figure on this page.

Your measurements are processed inside your own browser. Height, weight, age and anything else you enter never leave your device, nothing is logged, and nothing survives closing the tab.

• Shows daily calories, of that, bmr, from activity, with your adjustment and weekly total together, so you are not running it twice
• A results table you can read across
• Updates as you type, with no button to press and no page reload
• Copy the result in one click
• Free, no sign-up, and it runs entirely in your browser

The calorie calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Estimating maintenance calories as a starting point
• Seeing how much activity level changes daily needs
• Converting a daily target into a weekly one
• Comparing your assumed activity level with the alternatives