About Core Conversions Conversions
Core conversions are the everyday unit changes that appear on almost every laboratory report. They cover the big concentration pairs — mmol/L to mg/dL, µmol/L to mg/dL, nmol/L to ng/mL — as well as electrolyte units (mEq/L and mmol/L), enzyme activity (U/L and µkat/L), and simple mass conversions like mg/L to mg/dL. If you are trying to compare a result from a US report with one written in SI units, this is usually where to start.
The key idea running through all of these tools is that most conversions between mass and molar units are set by the molecule's weight, so every analyte has its own factor. Glucose uses about 18, creatinine 88.4, and bilirubin 17.1 — which is why a single generic number cannot work for every test. Each calculator here shows the factor and the formula, and the SI unit conversion calculator converts 29 analytes at once if you are not sure which tool you need.