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Weight

Convert ounces to grains

1 oz=437.5gr

Use the converter below to change any ounces value into grains instantly — with formula, conversion table, and real-world examples.

437.5

Conversion formula

Forward
grains = ounces × 437.5
Reverse
ounces = grains × 0.002286

Example: 10 oz × 437.5 = 4,375 gr.

About both units

From

Ounce

oz

The ounce equals 28.35 grams and is 1/16 of a pound. It is common in American and British cooking for small ingredient weights. The fluid ounce (29.57 ml in the US, 28.41 ml in the UK) is a volume unit and is completely different from the mass ounce.

Real-world: A US tin of tuna is 5 oz (142 g). A Starbucks grande coffee is 16 fl oz (473 ml). Gold is traded in troy ounces (31.10 g).
Read full ounce reference →
To

Grain

gr

The grain equals 64.79891 milligrams exactly, one of the oldest units of mass. Originally defined as the weight of a single grain of barley. Today used almost exclusively in firearms (bullet and gunpowder weights) and pharmaceuticals.

Real-world: A 9 mm bullet typically weighs 115–124 grains (7.45–8.03 g). Aspirin grain dosing: "5 grain aspirin" = 325 mg.
Read full grain reference →

Ounce to Grain conversion table

Common ounces to grains values for quick reference.

Ounce (oz)Grain (gr)
1 oz437.5 gr
5 oz2,187.5 gr
10 oz4,375 gr
25 oz10,937.5 gr
50 oz21,875 gr
100 oz43,750 gr
250 oz109,375 gr
500 oz218,750 gr
1,000 oz437,500 gr
5,000 oz2,187,500 gr

Tips & common mistakes

Quick tips

  • 1 oz = 28.35 g exactly (avoirdupois); 1 troy oz = 31.10 g.
  • 16 oz = 1 lb in the avoirdupois system used for food.
  • When converting a US recipe, 1 oz ≈ 2 tablespoons of a liquid ingredient.

Avoid these

  • Confusing mass ounces (28.35 g) with fluid ounces (volume).
  • Using avoirdupois ounces (28.35 g) for precious-metal pricing — gold is in troy ounces (31.10 g).
  • Multiplying lb × 16 and calling the result oz — correct only for weight, not volume.

Frequently asked questions

How many grains in a ounce?
One ounce equals 437.5 grains.
How do I convert ounces to grains?
Multiply the ounce value by 437.5 to get the equivalent in grains.
What is 100 ounces in grains?
100 ounces equals 43,750 grains.
Is a ounce bigger than a grain?
Yes. 1 ounce equals 437.5 grains, so one ounce is larger.
How to convert ounces to grains without a calculator?
Multiply by 437.5 for a quick estimate; use a calculator for precise results.

Related weight conversions

📊 See full comparison matrix →

More from Ounce

oz → kg
1 = 0.02835 kg
oz → g
1 = 28.3495 g
oz → mg
1 = 28,349.52 mg
oz → µg
1 = 28,349,523.13 µg
oz → lb
1 = 0.0625 lb
oz → t
1 = 2.8350e-5 t
oz → ton (US)
1 = 3.1250e-5 ton (US)
oz → ton (UK)
1 = 2.7902e-5 ton (UK)

More to Grain

kg → gr
1 = 15,432.36 gr
g → gr
1 = 15.4324 gr
mg → gr
1 = 0.01543 gr
µg → gr
1 = 1.5432e-5 gr
lb → gr
1 = 7,000 gr
t → gr
1 = 15,432,358.35 gr
ton (US) → gr
1 = 14,000,000 gr
ton (UK) → gr
1 = 15,680,000 gr

Conversions in other categories

LengthKilometer → MileTemperatureCelsius → FahrenheitVolumeLiter → US GallonAreaSquare Meter → Square FootSpeedKilometer per Hour → Mile per HourEnergyKilojoule → KilocaloriePressureBar → Pound per Square InchPowerKilowatt → Mechanical Horsepower