Health calculators
Run the numbers — and understand them.
Free calculators that don't just give you a number. Each one shows where your result falls on a clear visual scale and explains, in plain language, what it means and what to consider next. Nothing is saved.
- Body composition BMI calculator Estimate your body mass index from your weight and height, and see what the number means in plain language — with the usual caveats about what BMI can and cannot tell you. Open calculator
- Heart & circulation Blood pressure category Enter a systolic and diastolic reading to see where it falls on the ACC/AHA blood pressure chart, with a plain-language explanation of what that category means. Open calculator
- Blood sugar HbA1c to average glucose Convert your HbA1c percentage into an estimated average glucose (eAG) in mg/dL and mmol/L, and see how the value maps onto the normal, prediabetes, and diabetes ranges. Open calculator
- Heart & metabolic risk Cholesterol ratio Work out your total-cholesterol-to-HDL ratio and your non-HDL cholesterol from your lipid panel, and see how the ratio fits into cardiovascular risk — with the caveat that it is only one piece. Open calculator
- Kidney function eGFR calculator Estimate your glomerular filtration rate from your creatinine, age, and sex using the race-free CKD-EPI 2021 equation, and see the corresponding kidney-function stage explained. Open calculator
- Kidney function Creatinine clearance calculator Estimate creatinine clearance from age, sex, body weight, and serum creatinine using the Cockcroft-Gault equation, the formula much drug-dosing guidance is still written against. Open calculator
- Metabolism Corrected calcium calculator Adjust a total serum calcium for a low or high albumin using the Payne formula, and see how the corrected figure compares with the standard reference range. Open calculator
- Metabolism Anion gap calculator Calculate the serum anion gap from sodium, chloride, and bicarbonate, with an optional albumin correction, and see how the result is used to work up a metabolic acidosis. Open calculator
- Liver FIB-4 calculator Estimate the FIB-4 index from age, AST, ALT, and platelet count, with the age-adjusted lower cutoff applied automatically, and see how the score is used to triage advanced liver fibrosis. Open calculator
Reading a full panel? Try the lab results explainer →
This is general health information, not a diagnosis. Reference ranges vary by laboratory and by person — use the values on your own report and talk to a clinician about what they mean for you.