Guides
The questions behind the numbers.
A calculator gives you a figure. These explain where it came from, how much to trust it, and what to do when it disagrees with the one you got somewhere else.
Guide
How big a calorie deficit do you actually need?
What a calorie deficit is, the arithmetic behind losing 1 lb or 0.5 kg a week, and why the familiar 3,500-calorie rule overpromises.
Guide
BMR vs TDEE: what's the difference?
BMR is what you burn at complete rest; TDEE is your whole day. Which number to use for a calorie target, and why they are never the same.
Guide
Why do TDEE calculators give you different numbers?
Four reasons two calculators disagree by hundreds of calories for the same person — and how to tell which number to trust.
Guide
How to choose your activity level honestly
Activity level is the biggest lever in any calorie calculation and the easiest to get wrong. How to pick the bucket that matches your real week.
Guide
What are maintenance calories?
Maintenance calories are the intake that holds your weight steady. How to estimate the number, and how to find your real one from the scale.
Guide
Is BMI accurate if you're muscular?
Why BMI reads muscle as excess weight, who it misclassifies, and what to look at alongside it when the number does not match the person.
Guide
How much protein do you need per day?
What the evidence says about daily protein for building muscle, why the benefit plateaus, and how that translates into grams for your body weight.
Health note
These guides explain how the calculations work. They are general information, not medical advice, and nothing here is a substitute for talking to a doctor or a registered dietitian about your own situation.
If you have a medical condition, are pregnant or breastfeeding, have a history of eating disorders, or are making a significant change to how you eat or train, consider speaking with a qualified healthcare professional.