Resources
Reference resources
Plain-English explanations of the key concepts behind your calorie needs.
These references explain the science behind the calculators on this site — what each measurement means, how it is estimated, and where the numbers come from. Use them alongside the tools to understand your results, then apply them with the relevant calculator. Each topic is written for everyday readers, not specialists.
What is BMR? What is TDEE? Mifflin-St Jeor Equation Calories Burned in a Day BMI Calculator Guide Body Fat Percentage Macro Calculator Guide TDEE Calculator Guide Lean Body Mass Guide Water Intake Calculator Protein Calculator Guide Protein to Calories Weight Loss Calculator Guide Ideal Body Weight Calorie Deficit Guide Calorie Surplus Guide