The research behind the numbers, in plain language.
Every guide here explains the reasoning a calculator on this site is built on — where the ranges come from, what they mean, and where they don’t apply.
Nutrition & body composition
How much protein do you actually need?
What the research says about protein needs by activity level, goal, and age — the reasoning behind our calculator’s ranges.
Read the guide Weight management · LiveUnderstanding TDEE and calorie needs
What “maintenance calories” actually means, and why two people the same size can need very different amounts.
Read the guide Vitals · LiveBody fat percentage, explained
How estimation methods work, how accurate they really are, and what the number can and can’t tell you.
Read the guide Body composition · LiveBMI and ideal body weight, explained
How BMI is calculated, why Asian populations use different action points, and what ideal body weight formulas are really for.
Read the guideHow to read a nutrition label
What’s actually required on a label, what’s marketing, and which numbers matter most for your goals.
In developmentProtein vs. calories for fat loss
Why protein intake matters even when the scale is the thing you’re actually watching.
In developmentChildren’s growth & dosing
How fast should a child grow?
Typical growth rates by age and puberty, why short intervals mislead, and how to measure height accurately.
Read the guide Paediatrics · LiveAvoiding paediatric dosing errors
Per-dose versus per-day, mg versus micrograms, and the other slips behind most tenfold dosing errors.
Read the guide Paediatrics · LiveIbuprofen for children, explained
How the 5–10 mg/kg dose is worked out, the age and weight limits, and how to convert a dose to millilitres.
Read the guide Paediatrics · LiveCefalexin dosing for children, explained
The BNFc/NICE regimen for standard and severe infections, and how it differs from other national guidelines.
Read the guideMedicines & monitoring
Comparing corticosteroid doses
How equivalent doses work, what they leave out, and why switching long-term steroids needs care.
Read the guide Medicines · LivePlanning a medicine taper
Fixed versus percentage reductions, why one schedule doesn’t suit every drug, and practical tips for a safer plan.
Read the guide Medicines · LiveMethotrexate: a once-weekly medicine
How BSA-based weekly dosing works and the safety checks that prevent accidental daily dosing.
Read the guide Medicines · LiveHow the Ganzoni formula estimates iron deficit
What each part of the formula means, which weight to use, and how the total is split into doses.
Read the guideScores & lab tests
Understanding the Risk of Malignancy Index
How RMI I is scored, what NICE’s threshold of 250 means, and what the index can and can’t tell you.
Read the guide Diabetes · LiveWhat HbA1c means in everyday glucose numbers
The ADAG equation that links HbA1c to average glucose, and why a single reading can’t be converted.
Read the guide