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Conversion Formula:
Convert Ounce to Carat (oz to ct) 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.
Carat (ct) — a metric unit of mass for gemstones
It is defined as exactly 200 milligrams, or one fifth of a gram. Used worldwide for measuring diamonds, gemstones, pearls, and other jewels; it should not be confused with karat, which measures gold purity.
- Symbol: ct
- System: Non-SI metric unit for mass; used with SI
- Exact relations: 1 ct = 200 mg = 0.2 g = 0.0002 kg
- Imperial equivalents (derived from 1 lb = 0.45359237 kg exactly): 1 ct ≈ 0.00705479 oz ≈ 0.000440925 lb
- Typical examples: a small diamond ~0.25 ct; an engagement-ring diamond ~1 ct; large gemstones may be several ct.