The conversions health and supplement readers actually need — mg ↔ mcg ↔ g, kg ↔ lb, mL ↔ teaspoon, °C ↔ °F — plus a substance-correct IU ↔ mcg converter for vitamin D, A, and E. Because there is no single "IU to mg" number, and getting it wrong means getting your dose wrong.
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IU measures biological activity, not mass — so the conversion depends on the exact substance. Pick the vitamin, then enter the IU on the label.
Mixing milligrams and micrograms is one of the most common supplement and medication errors. 1 mg = 1,000 mcg. A label reading "1000 mcg" of B12 is the same as 1 mg — comparing products means converting first.
An International Unit measures biological effect, so 1 IU of vitamin D, A, and E each weighs a different amount. There is no universal "IU to mg." That's why the converter makes you choose the substance — a single factor would mislead.
A "teaspoon" is 4.93 mL by definition, but real spoons vary widely. For liquid supplements or medication, use a marked oral syringe or dosing cup — see the reconstitution tool for injectable dosing.
A general-purpose unit converter for health and supplement contexts. Conversion factors are standard reference values; IU factors follow common pharmacopeial conventions. This does not replace the dosing instructions on your specific product or your clinician's guidance — when a medication or supplement label states a dose, follow the label.
No — and confusing them is a common dosing error. 1 milligram (mg) = 1,000 micrograms (mcg or µg). So 0.5 mg is 500 mcg, and 250 mcg is 0.25 mg. Many supplements (vitamin D, B12, folate, peptides) are dosed in mcg, while others use mg, so always check the unit before comparing products.
1,000 IU of vitamin D3 equals 25 mcg, because 1 mcg of vitamin D = 40 IU. So 2,000 IU = 50 mcg and 5,000 IU = 125 mcg. Note this 40-IU-per-mcg factor is specific to vitamin D — it does not apply to other vitamins.
Because an International Unit (IU) measures biological activity, not mass — and each substance has a different activity per milligram. 1 IU of vitamin D, vitamin A, vitamin E, and insulin all weigh different amounts. That's why the converter above requires you to pick the specific substance for IU conversions; a generic "IU to mg" number would be wrong for most compounds.
Multiply kilograms by 2.20462 to get pounds (e.g. 80 kg × 2.20462 ≈ 176.4 lb). To go the other way, multiply pounds by 0.453592 (e.g. 180 lb × 0.453592 ≈ 81.6 kg).
One US teaspoon is 4.93 mL (commonly rounded to 5 mL), and one US tablespoon is 14.79 mL (≈15 mL). For accurate supplement or liquid medication dosing, use a marked oral syringe or dosing cup rather than kitchen cutlery, which varies widely.