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Conversion Formula:
Convert Ounce to Grain (oz to gr) instantly with accurate, readable results.
Use our Mass Unit Converter to convert between grams, kilograms, pounds, ounces, and other weight units instantly. Designed for cooking, science, fitness, and engineering needs, this unit conversion tool offers accurate results between metric and imperial systems. Whether you’re tracking body weight, measuring ingredients, or handling heavy machinery, our mass unit conversion calculator has you covered.
Ounce (oz) — an imperial and US customary unit of mass
It is defined as exactly one sixteenth of an avoirdupois pound; since 1 lb = 0.45359237 kg exactly, 1 oz = 28.349523125 g exactly. Used in the United States and some other countries for measuring food, packages, precious metals, and everyday small masses.
- Symbol: oz
- System: Imperial and US customary unit for mass
- Exact relations: 1 oz = 1/16 lb = 28.349523125 g = 28,349.523125 mg
- Metric equivalents: 1 oz ≈ 28.3495 g ≈ 0.0283495 kg
- Typical examples: a slice of bread ~1 oz; a letter ~1 oz; a small bag of chips ~1 oz.
Grain (gr) — a small imperial and US customary unit of mass
It is defined as exactly 1/7000 of an avoirdupois pound; since 1 lb = 0.45359237 kg exactly, 1 gr = 64.79891 mg exactly. Used mainly for measuring bullets, gunpowder, arrows, and some pharmaceutical or historical masses.
- Symbol: gr
- System: Imperial and US customary unit for mass
- Exact relations: 1 gr = 1/7000 lb = 1/437.5 oz = 64.79891 mg
- Metric equivalents: 1 gr = 0.06479891 g ≈ 0.0000647989 kg
- Typical examples: a small bullet ~40 gr; a larger rifle bullet ~150 gr; an aspirin tablet was historically 5 gr.