Mg to oz converter, one ounce is 28,349.523 milligrams.

To convert mg to oz, divide the milligrams by 28,349.523125, or multiply by 0.000035274. One ounce is 28,349.523125 mg, so 1,000 mg is 0.035274 oz, 500 mg is 0.017637 oz and 28,350 mg is almost exactly one ounce. The ounce here is the one on a kitchen scale, the avoirdupois ounce. For the other direction, 1 oz × 28,349.523 gives milligrams.

How to use the converter

1. Type the amount in the Milligrams (mg) box. A decimal or a big number such as 28350 works.
2. The big result shows Ounces (oz). Use Decimals in the side column to fix the number of places.
3. The cards under the result show the same amount in other units.
4. Type in the second box, or press ⇄, to go the other way.
5. Click a row in Common values to load it. Copy result, Copy link, Copy table and Print chart keep the answer. Start again resets the box.
6. Under the tables, Convert a list takes many amounts at once. Paste one per line, for example a column from a spreadsheet, and read them all in the units shown above. Copy results copies the table, and the swap button turns the list around.

Where 28,349.523125 comes from

NIST Handbook 44 (2026), Appendix C lists the avoirdupois pound as 453.59237 grams exactly and the avoirdupois ounce as one sixteenth of it, 28,349.523125 milligrams. It gives the milligram as 0.001 gram exactly. Checked 26 Oct 2026. So the sum is exact too, and the long number is an exact value, not a rounded one. The Handbook also lists the ounce as 437.5 grains.

Three ounces, three answers

The fluid ounce (fl oz) is a volume, and it has no conversion from milligrams without a density. This page is about weight only.

Milligrams to ounces, in a table

Worked examples

• 1,000 mg. 1,000 ÷ 28,349.523 = 0.035274 oz.
• 500 mg. 0.017637 oz, or 0.5 g.
• 100,000 mg. 3.5274 oz, which is 0.22046 lb.
• 28,000 mg, the label ounce. 0.98767 oz, a little under 1.
• Ounces back to mg. 0.25 oz × 28,349.523 = 7,087.3808 mg.

Why the number is so small

An ounce is a large unit for a milligram. It takes 28,350 mg to make one. So a pill of 500 mg is under 2 percent of an ounce (0.0176 oz) and a decimal with four zeros shows up. The Auto setting adds places for tiny answers so four digits always show. If you want a fixed number of places in the table, pick a number in Decimals. A kitchen scale that reads to 1 g or to 0.1 oz cannot weigh a few milligrams, whatever the conversion shows.

This page is a unit converter. It changes one unit of mass into another and nothing more. It does not say how much of anything is right for you. For a medicine, a vitamin or a supplement, follow the label and ask a doctor or a pharmacist.

See also Mg to grams, Grams to ounces, Ounces to grams and Mg to lbs.