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Convert Ounce to Milligram

Use this free converter to change ounces (oz) into milligrams (mg). Ounce and milligram both measure weight & mass. As a quick reference, 1 oz equals 28349.523 mg, and 1 mg equals 0.000035273962 oz.

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Milligram (mg)
28349.523

1 oz = 28349.523 mg

Weight & Mass conversion table

OunceMilligram
0.01283.49523
0.12834.9523
0.514174.762
128349.523
256699.046
385048.569
5141747.62
10283495.23
20566990.46
25708738.08
501417476.2
1002834952.3
1,00028349523

How to convert Ounce to Milligram

Multiply the ounce value by 28349.523 to get milligrams.

  1. Enter the number of ounces you want to convert.
  2. The converter instantly shows the equivalent value in milligrams.
  3. Worked example: 15 oz × 28349.523 = 425242.85 mg.
  4. Use the swap button to reverse the conversion (milligram to ounce).

About these units

Ounce (oz)

Definition
An ounce (oz) is an imperial unit of mass equal to one sixteenth of a pound, about 28.35 grams.
History
It also descends from the Roman "uncia" (a twelfth) and was later fixed at 1/16 of the avoirdupois pound.
Current use
Ounces measure food portions, postal weights, and ingredients in the US and UK.

Milligram (mg)

Definition
A milligram (mg) is one thousandth of a gram, used for very small masses such as medication doses.
History
It is a standard metric subdivision using the prefix "milli-" (one thousandth).
Current use
Milligrams express drug dosages, vitamin content, and quantities in chemistry and pharmacology.

Frequently asked questions

How many milligrams are in a ounce?

There are 28349.523 mg in 1 oz. To convert, multiply the number of ounces by 28349.523.

How do I convert ounces to milligrams?

Multiply the ounce value by 28349.523 to get milligrams. For example, 10 oz = 283495.23 mg.

Is this ounce-to-milligram converter free?

Yes. This converter is completely free, runs entirely in your browser, and requires no sign-up. Your inputs never leave your device.

Convert Ounce to other weight & mass units

Unit1 Ounce equals
Kilogram (kg)0.028349523 kg
Gram (g)28.349523 g
Milligram (mg)28349.523 mg
Microgram (µg)28349523 µg
Metric Ton (t)0.000028349523 t
Pound (lb)0.0625 lb
Stone (st)0.0044642857 st
US Ton (ton)0.00003125 ton
Imperial Ton (long ton)0.000027901786 long ton
Carat (ct)141.74762 ct

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