International units converter v. 3.0

Easily convert IU ⇄ g/mg/mcg



List of substances

User manual

In order to convert some quantity of substance (or active pharmaceutical ingredient) please follow next steps:

  • In the field Group of substances select a required group.
  • In the field Substance select a substance from previously selected group.
  • In the field Quantity enter your quantity of substance (or active pharmaceutical ingredient).
  • In the field From select initial units.
  • In the field To select target units.
  • In the field Decimal places enter a number of decimal places displayed in the result.
  • Press button Convert. Result will appear under the button.

If you entered, for example, 1000000, and obtained 0.00 as a result, please increase the precision to 6-7 decimal places or switch units to smaller. Some substances have very small conversion factors in some directions, so the obtained results will be also very small. For convenience, under the rounded result unrounded one will display.

We hope this converter will be useful for you!

Information about «International units»

International unit (IU) — In pharmacology, the international unit is a unit of measurement for the amount of a substance; the mass or volume that constitutes one international unit varies based on which substance is being measured, and the variance is based on the biological activity or effect, for the purpose of easier comparison across substances. International units are used to quantify vitamins, hormones, some medications, vaccines, blood products, and similar biologically active substances. Many biological agents exist in different forms or preparations (e.g. vitamin A in the form of retinol or beta-carotene). The goal of the IU is to be able to compare these, so that different forms or preparations with the same biological effect will contain the same number of IUs. To do so, the WHO Expert Committee on Biological Standardization provides a reference preparation of the agent, arbitrarily sets the number of IUs contained in that preparation, and specifies a biological procedure to compare other preparations of the same agent to the reference preparation. Since the number of IUs contained in a new substance is arbitrarily set, there is no equivalence between IU measurements of different biological agents. For instance, one IU of vitamin E cannot be equated with one IU of vitamin A in any way, including mass or efficacy. Despite its name, IU is not part of the International System of Units used in physics and chemistry. The IU should not be confused with the enzyme unit, also known as the international unit of enzyme activity and abbreviated as U.

International unit (IU) — Internationally agreed-upon standards are necessary to compare the potency of various biologically assayed compounds in terms of their activity. If it is not possible to purify chemically the substance to be bioassayed, a stable standard solution has to be employed for comparison. Standards for sera are held at the State Serum Institute, Copenhagen, the National Institute for Medical Research at Mill Hill, UK. and by the WHO. An International Unit is defined as a particular quantity of the standard preparation (one IU of tetanus antitoxin is 0.1547 mg of a preparation held in Copenhagen).

New in version 3.0

  • Reviewed all substances and their conversion factors. Added links on reliable sources for each substance.
  • Deleted controversial substances with not confirmed data.
  • Substances divided into groups.
  • Edited names of some substances.
  • Added synonyms for some substances.
  • Added unrounded result to the output. It is useful when you get zero result. Unrounded result will show that you have to change target units to smaller (for example from mg to mcg).
  • Converter adapted to mobile devices.