Convert Troy Ounce to Pennyweight
Convert troy ounces to pennyweights instantly. 1 troy ounce = 20.0000005144 pennyweight — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Pennyweight to Troy Ounce converter for the reverse conversion.
Units explained
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.
Pennyweight
The pennyweight (dwt) equals one-twentieth of a troy ounce, 24 grains (about 1.555 g).
From the mass of a medieval English silver penny; symbol dwt from 'denarius weight'.
Jewelry making and precious-metal scrap valuation in the US.
Derived from the medieval English coinage system.
Troy Ounce to Pennyweight conversion formula
The relationship between troy ounces and pennyweights:
To convert troy ounces to pennyweights, multiply the value in troy ounces by 20.0000005144. To reverse, multiply pennyweights by 0.0499999987.
How to use this converter
Type a value into the calculator. The result in pennyweights updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Pennyweight to Troy Ounce converter for the reverse direction.
Step-by-step: convert troy ounces to pennyweights
- Write down the value in troy ounces (oz t).
- Multiply that value by the factor 20.0000005144.
- The product is the equivalent value in pennyweights (dwt).
- To reverse, multiply the pennyweight value by 0.0499999987.
Worked examples
Example 1 — Convert 1 oz t to dwt:
1 × 20.0000005144 = 20.0000005144 dwt
Example 2 — Convert 100 oz t to dwt:
100 × 20.0000005144 = 2000.0000514412 dwt
Real-world example — Hardware-scale dimensions
A 10-troy ounce fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between troy ounces and pennyweights daily when mixing metric and imperial tools.
10 oz t × 20.0000005144 = 200.0000051441 dwt
Real-world example — Postcard and small-object dimensions
A postcard is about 5 troy ounces wide. Converting to pennyweights is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 oz t × 20.0000005144 = 100.0000025721 dwt
Real-world example — Ruler-scale measurements
A 30-troy ounce school ruler converts cleanly to pennyweights — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 oz t × 20.0000005144 = 600.0000154324 dwt
Troy Ounce to Pennyweight conversion table
Standard reference values for converting troy ounces to pennyweights:
| Troy Ounce [oz t] | Pennyweight [dwt] |
|---|---|
| 0.01 | 0.2000000051 |
| 0.1 | 2.0000000514 |
| 1 | 20.0000005144 |
| 2 | 40.0000010288 |
| 3 | 60.0000015432 |
| 4 | 80.0000020576 |
| 5 | 100.0000025721 |
| 10 | 200.0000051441 |
| 20 | 400.0000102882 |
| 30 | 600.0000154324 |
| 40 | 800.0000205765 |
| 50 | 1000.0000257206 |
| 100 | 2000.0000514412 |
| 500 | 10000.000257206 |
| 1000 | 20000.000514412 |
Frequently asked questions
How many pennyweights is 1 troy ounce?
How do I convert troy ounces to pennyweights?
How do I convert pennyweights back to troy ounces?
How many pennyweights is 100 troy ounces?
Popular weight unit conversions
Convert Troy Ounce to other weight units
Show all Troy Ounce conversions
Metric / SI (18 units)
Avoirdupois (15 units)
Troy & Apothecary (9 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 oz t = 20.0000005144 dwt) 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.