How many carats are in a troy ounce?

One troy ounce equals approximately 155.517 carats (1 ozt = 31.1034768 g; 1 ct = 0.2 g, so 31.1034768 / 0.2 = 155.517 ct).

How many carats are in an avoirdupois ounce?

One avoirdupois ounce equals approximately 141.748 carats (1 oz = 28.3495 g; 28.3495 / 0.2 = 141.748 ct).

What is the difference between a troy ounce and a regular ounce?

A troy ounce (ozt) is 31.1035 g, used for precious metals and gemstones. An avoirdupois ounce (oz) is 28.3495 g, used in everyday commerce. Troy ounce is about 10% heavier than the common ounce.

Is a carat the same as a karat?

No. A carat (ct) is a unit of mass equal to 200 mg, used for gemstones. A karat (kt or k) is a measure of gold purity (24 karat = pure gold). They sound the same but measure different things.

How accurate is this converter?

The converter uses the internationally defined values: 1 ct = 0.2 g exactly, 1 troy oz = 31.1034768 g, and 1 avoirdupois oz = 28.349523125 g. Results are displayed to 6 significant figures.

Carats to Ounces Converter

Name: Carats to Ounces Converter
Availability: InStock
Author: Nham Vu

Enter a mass in carats and instantly get the equivalent in troy ounces and avoirdupois ounces.

Enter Weight in Carats

Carats (ct)

Quick presets

Conversion Factors

1 ct = 0.200000 g (exact)
1 troy oz (ozt) = 31.103477 g
1 avoirdupois oz = 28.349523 g

Conversion Results

Enter a value in carats to see results

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Summary

Enter a mass in carats and instantly get the equivalent in troy ounces and avoirdupois ounces.

How it works

Enter the mass value in carats in the input field.
The converter multiplies by 0.2 to get grams (1 ct = 200 mg = 0.2 g).
Grams are divided by 31.1034768 to produce troy ounces.
Grams are divided by 28.349523125 to produce avoirdupois ounces.
Results update instantly as you type and can be copied with one click.

Use cases

Convert gemstone weights from carats to ounces for export documentation.
Compare diamond or ruby weights to precious-metal standards.
Calculate jeweler invoices that mix carat and troy-ounce pricing.
Cross-check lab balances reporting in carats against ounce-based scales.
Convert carat weights for customs and shipping forms.
Translate gemological reports into ounce values for retail labeling.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu