What this result means
Choose cholesterol or triglycerides as well as the direction. Cholesterol uses mg/dL × 0.0259 to reach mmol/L, while triglycerides use mg/dL × 0.0113. The factors are different, so the test name must stay attached to the number. [1][2]
Choose the test before the unit
The concentration stays the same
Milligrams per decilitre express mass concentration, while millimoles per litre express amount concentration. The formula changes how the same laboratory concentration is written; it does not alter the sample or create a new test result. [1]
This does not calculate a missing lipid result
A unit conversion is different from estimating LDL-C, calculating non-HDL-C, forming a cholesterol ratio or assessing cardiovascular risk. This page performs none of those calculations and does not add a health category to the converted value.
How the result is rounded
The calculator uses exact decimal arithmetic with 0.0259 for cholesterol or 0.0113 for triglycerides and divides by the same selected factor in the reverse direction. It rounds once to two decimal places; an exact halfway tie rounds upward in magnitude. A positive value below 0.01 is shown as less than 0.01, and extra displayed digits do not make a rounded source result more precise. [1][2]
Safe next steps
Keep the original laboratory report beside the converted number and confirm the test name, original unit and decimal point. For health meaning or treatment decisions, use the reference information printed by the same laboratory and discuss the full lipid panel and your wider risk factors with a qualified clinician.
Formula and assumptions
- Formula
- Cholesterol (mmol/L) = cholesterol (mg/dL) × 0.0259; cholesterol (mg/dL) = cholesterol (mmol/L) ÷ 0.0259. Triglycerides (mmol/L) = triglycerides (mg/dL) × 0.0113; triglycerides (mg/dL) = triglycerides (mmol/L) ÷ 0.0113. [1][2]
- Version
- Cholesterol and triglyceride conventional-to-SI unit conversion, lipid-panel-conventional-si-unit-conversion-v1
- Rounding
- Use exact decimal arithmetic with each published forward factor and its stored inverse, then round once to two decimal places. An exact halfway tie rounds upward in magnitude. Positive values below display resolution use a less-than result; source-laboratory rounding is not corrected.
Who this is for — and when not to use it
Intended use
Neutral conversion of one existing laboratory-reported total cholesterol, LDL-C, HDL-C, non-HDL-C or triglyceride concentration between mg/dL and mmol/L while preserving the selected analyte.
Not intended for
This tool does not interpret a lipid result, apply a target or health band, calculate LDL-C or non-HDL-C, combine a lipid panel, convert ApoB, ApoA1 or Lp(a), assess cardiovascular risk, diagnose a condition, or guide treatment.
Exclusions
- Result interpretation, target ranges, diagnosis or cardiovascular-risk assessment
- Calculating LDL-C, non-HDL-C, VLDL-C, ratios or any missing lipid result
- ApoB, ApoA1, lipoprotein(a), glucose or any analyte other than cholesterol and triglycerides
- Mass concentrations other than mg/dL or amount concentrations other than mmol/L
- Medication decisions, treatment monitoring or urgent-care decisions
- Changing the reported test name or applying one analyte's factor to another
- Reconstructing greater precision than the source laboratory reported
Evidence sources
- 1. Diabetes in America, 3rd Edition, Appendix 1: Conversions — National Institute of Diabetes and Digestive and Kidney Diseases. Accessed Aug 10, 2026.
- 2. AIM-HIGH Study Protocol — National Heart, Lung, and Blood Institute BioLINCC. Accessed Aug 10, 2026.