Heart & coagulation

von Willebrand factor antigen unit converter

Amount of von Willebrand factor protein (bleeding disorder workup)

Also known as: vWF antigen, VWF:Ag

Converter

Enter a value in any unit and all other units fill in.

IU/mL % = IU/dL

Worked example

95 % (middle of the reference range) = 0.95 IU/mL

Conversion formulas

IU/mL	IU/mL = % × 0.01	% = IU/mL × 100

Good to know

The amount of von Willebrand factor protein is reported in % or in IU/dL (identical) or IU/mL.

1 IU/dL = 1 %; 1 IU/mL = 100 %.
The level rises with stress, pregnancy and inflammation, which can hide a mild deficiency.

Reference range

Unit	Adults
IU/mL	0.4 – 1.5
% = IU/dL	40 – 150

Source: Newcastle Hospitals Laboratories: vW Factor Antigen · Last reviewed: 2026-10-19

Note from the source: 40-150 IU/dL (= 40-150 %) (Newcastle Hospitals Laboratories); blood group O has lower values. Assay-specific

Frequently asked questions

How do I convert von Willebrand factor antigen from % to IU/mL?

IU/mL = % × 0.01. In the other direction: % = IU/mL × 100.

What is the reference range of von Willebrand factor antigen?

For adults the range is 40 – 150 % (Newcastle Hospitals Laboratories: vW Factor Antigen). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for von Willebrand factor antigen?

Common units are IU/mL, %.