This mg to mcg converter switches between grams, milligrams, micrograms, and nanograms, and converts to international units (IU) when you know the substance’s factor.
How to use the mg to mcg to IU Converter
- Enter the value.
- Select the from.
- Select the to.
- Enter the iu conversion factor, or tap a preset when it appears.
- Read the result card. It updates as you type, and you can copy or share it.
About this calculator
Mass units scale by factors of 1,000. Mixing up mg and mcg is one of the most common dosing errors, because it changes the amount a thousandfold.
International units (IU) measure biological activity, not mass. There is no universal mg-to-IU conversion. Each substance has its own factor set against a WHO reference standard.
Frequently asked questions
Is mcg the same as µg?
Yes. Both mean microgram. US medical writing uses "mcg" because "µg" can be misread as "mg".
Why is IU not always available?
IU depends on the substance. Enter the factor from the product label or reference standard to enable it.
Sources
- SI units and prefixes. National Institute of Standards and Technology.
- WHO Expert Committee on Biological Standardization. World Health Organization.
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Medical disclaimer. This calculator is for educational purposes only and is not medical advice. Results are mathematical estimates based on the values you enter. Many peptides listed here are not approved by the FDA for human use. Confirm every dose with a licensed healthcare provider or your approved study protocol, and follow the product label.
