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Convert Ounces to Milligrams

1 ounce is 28,349.523125 mg. One ounce is exactly 28349.523125 milligrams.

One ounce is 28349.523 milligrams. To convert ounces to milligrams, multiply by 28349.523; to go the other way, divide by 28349.523 or multiply by 3.5274 × 10^-5. The factor is exact rather than rounded: it follows from NIST Handbook 44. One sixteenth of a pound.

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Milligrams
28,349.523125 mg
Ounces × 28349.523
value * 28349.52312528,349.523 mg

1 ounce in every weight unit

UnitValueExact factor
ounces (as entered)1 oz
pounds0.0625 lb× 0.0625
stone0.004464285714 st× 0.00446428571429
US tons0.00003125 ton× 0.00003125
micrograms28,349,523.13 mcg× 28,349,523.125
milligrams28,349.52313 mg× 28,349.523125
grams28.34952313 g× 28.349523125
kilograms0.02834952313 kg× 0.028349523125
tonnes0.00002834952313 t× 0.000028349523125

Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert ounces to milligrams?

  1. 1.Take the measurement in ounces.
  2. 2.Multiply by 28349.523 — that is how many milligrams fit in one ounce.
  3. 3.To go back the other way, divide by 28349.523, or multiply by 3.5274 × 10^-5.

Ounces to milligrams conversion table

OuncesMilligrams
1 oz28,349.523125 mg
2 oz56,699.04625 mg
3 oz85,048.569375 mg
4 oz113,398.0925 mg
5 oz141,747.615625 mg
6 oz170,097.13875 mg
7 oz198,446.661875 mg
8 oz226,796.185 mg
9 oz255,145.708125 mg
10 oz283,495.23125 mg
12 oz340,194.2775 mg
15 oz425,242.846875 mg
20 oz566,990.4625 mg
25 oz708,738.078125 mg
50 oz1,417,476.15625 mg
100 oz2,834,952.3125 mg

What are ounces and milligrams?

Ounce (oz)
One sixteenth of a pound. Not to be confused with the fluid ounce, which measures volume.
Milligram (mg)
One thousandth of a gram, and exactly 1,000 micrograms. The unit almost every medicine is dosed in.

Source: NIST Handbook 44 — mass and weight

Questions people actually ask

How many milligrams are in an ounce?
28349.523. One thousandth of a gram, and exactly 1,000 micrograms. The unit almost every medicine is dosed in.
How do I convert milligrams back to ounces?
Divide by 28349.523, or multiply by 3.5274 × 10^-5 — they are the same operation.

Other weight conversions

Milligrams to ounces — the same conversion the other way.

Calculators that work in weight