Free tools
Check the numbers a workup often needs
Use four calculators for figures that come up in a clinical assessment or referral. Each one runs in your browser on a published formula.
Calculators
Pick the question you have
- Pack-year calculatorEnter packs or cigarettes per day and the years smoked, for as many periods as the history has. Get the total in pack-years.
- BMI calculatorEnter weight and height in US or metric units. Get the BMI and where it sits in the WHO adult classification.
- QTc calculatorEnter the measured QT and the heart rate or RR interval. Get the corrected QT by both Bazett and Fridericia.
- CKD-EPI 2021 eGFR calculatorEnter serum creatinine in mg/dL or µmol/L, age and sex. Get the eGFR and its KDIGO category.
Method
Check how each calculator works
We name every formula
Each page names the formula it uses and its limits, so you can check the working before you rely on it.
We test against reference values
We test every formula against worked examples. When the inputs cannot give an answer, the calculator says so.
We keep your figures in your browser
We never send or store anything you type.