Heart & coagulation

Factor XI activity unit converter

Activity of coagulation factor XI

Also known as: Factor XI, FXI, Faktor XI, Coagulation factor XI

Converter

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

IU/mL % = IU/dL

Worked example

115 % (middle of the reference range) = 1.15 IU/mL

Conversion formulas

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

Good to know

The activity of coagulation factor XI is reported in % or in IU/dL (identical) or in IU/mL.

1 IU/dL = 1 %; 1 IU/mL = 100 %.
Children, newborns and people on anticoagulants have different values, so the range shown applies to untreated adults.

Reference range

Unit	Adults
IU/mL	0.7 – 1.6
% = IU/dL	70 – 160

Source: Newcastle Hospitals Laboratories: Factor XI Assay · Last reviewed: 2026-10-19

Note from the source: 70-160 IU/dL (= 70-160 %) (Newcastle Hospitals Laboratories). Children have different ranges; assay-specific

Frequently asked questions

How do I convert Factor XI activity from % to IU/mL?

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

What is the reference range of Factor XI activity?

For adults the range is 70 – 160 % (Newcastle Hospitals Laboratories: Factor XI Assay). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for Factor XI activity?

Common units are IU/mL, %.