Cholesterol measurements are usually displayed in one of two ways on a laboratory report: in mg/dL or mmol/L. The mg/dL measurement is more commonly seen in the US, whereas cholesterol readings in mmol/L are mostly used in other countries.
However, converting between these two measurements may be important –- especially if you want to compare your numbers to those in a guideline or other document where the measurements are listed differently. So, if you want to learn how to convert your LDL or HDL cholesterol levels from mg/dL to mmol/L, or vice versa, you can follow these simple steps:
Converting mg/dL to mmol/L:
To convert your LDL or HDL cholesterol number from mg/dL to mmol/L, you should multiply the number by 0.0259. For example, if your LDL cholesterol level was 200 mg/dL, you can convert it to mmol/L by performing this calculation:200 mg/dL x 0.0259 = 5.18 mmol/L
Converting mmol/L to mg/dL:
To convert your LDL or HDL cholesterol levels from mmol/L to mg/dL, you can divide the number given in mmol/L by 0.0259. An example of this conversion would be if you had an LDL cholesterol level of 4.8 mmol/L and wish to convert it to mg/dL:
4.8 mmol/L ÷ 0.0259 = 185 mg/dL
Sources:
Journal of the American Medical Association Editorial Guidelines. 2010. Available at: http://jama.ama-assn.org/content/vol295/issue1/images/data/103/DC6/JAMA_auinst_si.dtl. Accessed 18 January 2010.

