Convert Pennyweight to Carat (metric)
Convert pennyweights to carats (metric) instantly. 1 pennyweight = 7.775869 carat (metric) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Carat (metric) to Pennyweight converter for the reverse conversion.
Units explained
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.
Carat (metric)
The metric carat (ct) equals exactly 200 milligrams (0.0002 kg).
From Arabic 'qirat' and Greek 'keration', the carob seed once used as a counterweight.
The worldwide standard for gemstone and diamond mass.
The metric carat was fixed at 200 mg internationally in 1907.
Pennyweight to Carat (metric) conversion formula
The relationship between pennyweights and carats (metric):
To convert pennyweights to carats (metric), multiply the value in pennyweights by 7.775869. To reverse, multiply carats (metric) by 0.1286029896.
How to use this converter
Type a value into the calculator. The result in carats (metric) updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Carat (metric) to Pennyweight converter for the reverse direction.
Step-by-step: convert pennyweights to carats (metric)
- Write down the value in pennyweights (dwt).
- Multiply that value by the factor 7.775869.
- The product is the equivalent value in carats (metric) (ct).
- To reverse, multiply the carat (metric) value by 0.1286029896.
Worked examples
Example 1 — Convert 1 dwt to ct:
1 × 7.775869 = 7.775869 ct
Example 2 — Convert 100 dwt to ct:
100 × 7.775869 = 777.5869 ct
Real-world example — Adjacent metric sub-units
One pennyweight equals 1,000 carats (metric). Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 dwt × 7.775869 = 7.775869 ct
Real-world example — Adjacent small-scale precision
One pennyweight equals 1,000 carats (metric) — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 dwt × 7.775869 = 7.775869 ct
Pennyweight to Carat (metric) conversion table
Standard reference values for converting pennyweights to carats (metric):
| Pennyweight [dwt] | Carat (metric) [ct] |
|---|---|
| 0.01 | 0.07775869 |
| 0.1 | 0.7775869 |
| 1 | 7.775869 |
| 2 | 15.551738 |
| 3 | 23.327607 |
| 4 | 31.103476 |
| 5 | 38.879345 |
| 10 | 77.75869 |
| 20 | 155.51738 |
| 30 | 233.27607 |
| 40 | 311.03476 |
| 50 | 388.79345 |
| 100 | 777.5869 |
| 500 | 3887.9345 |
| 1000 | 7775.869 |
Frequently asked questions
How many carats (metric) is 1 pennyweight?
How do I convert pennyweights to carats (metric)?
How do I convert carats (metric) back to pennyweights?
How many carats (metric) is 100 pennyweights?
Popular weight unit conversions
Convert Pennyweight to other weight units
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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 dwt = 7.775869 ct) 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.