Use this online calculator to convert whole of blood results to plasma results, and vice versa.

Many blood glucose meters measure glucose level of the whole blood, whilst some just report the glucose levels of plasma – the fluid part of the blood.

Neither of these methods of testing is more accurate, they are simply different ways to measure the same levels.

Whole blood tests are typically approximately 12 per cent lower than plasma tests. The glucose content of whole blood is usually lower than the glucose content of plasma.

For those people that use a blood glucose meter calibrated for whole-blood, pre-prandial (before a meal) levels should stand between 80-120 mg/dl.

For bedtime, blood glucose should stand between 100-140 mg/dl. For those people using blood glucose meters calibrated for plasma alone, pre-meal should be 90-130 mg/dl, whilst bedtime goals should be 110-150 mg/dl.

Choose mmol/L readings (British standard) or mg/dL (American standard)

Due to an overwhelming number of requests, we have also provided this calculator in mmol/L as well as mg/dL.

To use this calculator accurately, you need to know what your meter is calibrated for. Numbers in the calculator are rounded down to a single decimal point.

Convert Whole Blood Results to Plasma Readings
Select measurement

You need to select

Whole Blood


Plasma Blood


With 20% clinical accuracy range:

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