Convert Ounce to Troy Ounce
Convert ounces to troy ounces instantly. 1 ounce = 0.9114583325 troy ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Troy Ounce to Ounce converter for the reverse conversion.
Units explained
Ounce
The (avoirdupois) ounce (oz) equals one-sixteenth of a pound, about 28.35 grams.
From Latin 'uncia', meaning a twelfth part.
US food portions, postal weights, and boxing weight classes.
Standardized as 1/16 of the international pound from 1959.
Troy Ounce
The troy ounce (ozt) equals about 31.103 grams, one-twelfth of a troy pound.
From the Troy system of weights associated with Troyes, France.
The global standard for pricing gold, silver, platinum, and palladium.
Established in the medieval Troy system and retained for precious metals.
Ounce to Troy Ounce conversion formula
The relationship between ounces and troy ounces:
To convert ounces to troy ounces, multiply the value in ounces by 0.9114583325. To reverse, multiply troy ounces by 1.0971428581.
How to use this converter
Type a value into the calculator. The result in troy ounces updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Troy Ounce to Ounce converter for the reverse direction.
Step-by-step: convert ounces to troy ounces
- Write down the value in ounces (oz).
- Multiply that value by the factor 0.9114583325.
- The product is the equivalent value in troy ounces (oz t).
- To reverse, multiply the troy ounce value by 1.0971428581.
Worked examples
Example 1 — Convert 1 oz to oz t:
1 × 0.9114583325 = 0.9114583325 oz t
Example 2 — Convert 100 oz to oz t:
100 × 0.9114583325 = 91.145833253 oz t
Real-world example — Hardware-scale dimensions
A 10-ounce fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between ounces and troy ounces daily when mixing metric and imperial tools.
10 oz × 0.9114583325 = 9.1145833253 oz t
Real-world example — Postcard and small-object dimensions
A postcard is about 5 ounces wide. Converting to troy ounces is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 oz × 0.9114583325 = 4.5572916626 oz t
Real-world example — Ruler-scale measurements
A 30-ounce school ruler converts cleanly to troy ounces — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 oz × 0.9114583325 = 27.3437499759 oz t
Ounce to Troy Ounce conversion table
Standard reference values for converting ounces to troy ounces:
| Ounce [oz] | Troy Ounce [oz t] |
|---|---|
| 0.01 | 0.0091145833 |
| 0.1 | 0.0911458333 |
| 1 | 0.9114583325 |
| 2 | 1.8229166651 |
| 3 | 2.7343749976 |
| 4 | 3.6458333301 |
| 5 | 4.5572916626 |
| 10 | 9.1145833253 |
| 20 | 18.2291666506 |
| 30 | 27.3437499759 |
| 40 | 36.4583333012 |
| 50 | 45.5729166265 |
| 100 | 91.145833253 |
| 500 | 455.7291662648 |
| 1000 | 911.4583325296 |
Frequently asked questions
How many troy ounces is 1 ounce?
How do I convert ounces to troy ounces?
How do I convert troy ounces back to ounces?
How many troy ounces is 100 ounces?
Popular weight unit conversions
Convert Ounce to other weight units
Show all Ounce conversions
Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 oz = 0.9114583325 oz t) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.