Convert Pound (troy/apothecary) to Carat (metric)
Convert pounds (troy/apothecary) to carats (metric) instantly. 1 pound (troy/apothecary) = 1866.208608 carat (metric) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Carat (metric) to Pound (troy/apothecary) converter for the reverse conversion.
Units explained
Pound (troy/apothecary)
The troy (apothecary) pound equals 12 troy ounces, about 373.24 grams.
Named for Troyes, France, a major medieval trade-fair town.
Historical pricing of precious metals; now largely superseded by the troy ounce.
Adopted as the English coinage standard under Henry VIII in 1528.
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.
Pound (troy/apothecary) to Carat (metric) conversion formula
The relationship between pounds (troy/apothecary) and carats (metric):
To convert pounds (troy/apothecary) to carats (metric), multiply the value in pounds (troy/apothecary) by 1866.208608. To reverse, multiply carats (metric) by 0.0005358458.
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 Pound (troy/apothecary) converter for the reverse direction.
Step-by-step: convert pounds (troy/apothecary) to carats (metric)
- Write down the value in pounds (troy/apothecary) (lb t).
- Multiply that value by the factor 1866.208608.
- The product is the equivalent value in carats (metric) (ct).
- To reverse, multiply the carat (metric) value by 0.0005358458.
Worked examples
Example 1 — Convert 1 lb t to ct:
1 × 1866.208608 = 1866.208608 ct
Example 2 — Convert 100 lb t to ct:
100 × 1866.208608 = 186620.8608 ct
Real-world example — Macro-to-micro scale comparison
2 pounds (troy/apothecary) of measurement converts to a very large number in carats (metric) — useful in materials science when comparing bulk-sample dimensions to feature-level surface specs.
2 lb t × 1866.208608 = 3732.417216 ct
Real-world example — Macroscopic to microscopic
One pound (troy/apothecary) equals a million carats (metric). Optical engineers calculating coherence length compare macro-scale path lengths with micro-scale wavelength differences using exactly this conversion.
1 lb t × 1866.208608 = 1866.208608 ct
Real-world example — Sub-meter precision
A 0.001-pound (troy/apothecary) (1 mm) tolerance equals 1,000 carats (metric) — useful for surface-finish specs, where macro-scale dimensions are given in the larger unit but feature roughness in the smaller.
0.001 lb t × 1866.208608 = 1.866208608 ct
Pound (troy/apothecary) to Carat (metric) conversion table
Standard reference values for converting pounds (troy/apothecary) to carats (metric):
| Pound (troy/apothecary) [lb t] | Carat (metric) [ct] |
|---|---|
| 0.01 | 18.66208608 |
| 0.1 | 186.6208608 |
| 1 | 1866.208608 |
| 2 | 3732.417216 |
| 3 | 5598.625824 |
| 4 | 7464.834432 |
| 5 | 9331.04304 |
| 10 | 18662.08608 |
| 20 | 37324.17216 |
| 30 | 55986.25824 |
| 40 | 74648.34432 |
| 50 | 93310.4304 |
| 100 | 186620.8608 |
| 500 | 933104.304 |
| 1000 | 1866208.608 |
Frequently asked questions
How many carats (metric) is 1 pound (troy/apothecary)?
How do I convert pounds (troy/apothecary) to carats (metric)?
How do I convert carats (metric) back to pounds (troy/apothecary)?
How many carats (metric) is 100 pounds (troy/apothecary)?
Popular weight unit conversions
Convert Pound (troy/apothecary) to other weight units
Show all Pound (troy/apothecary) 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 lb t = 1866.208608 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.