Zeptogram is 1e-21 gram units.
Zeptograms to Carats Converter — zg to ct
Convert Zeptogram (zg) to Carat (ct) using the exact conversion factor (1 zeptogram = 5e-21 carat). See the formula, worked examples, and conversion table.
Zeptograms to Carats converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
A metric carat is exactly 200 milligrams.
Result = input x 1e-24 / 0.0002.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Zeptograms to Carats
Weight conversions between Zeptogram and Carat come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Specifically: Zeptogram is 1e-21 gram units, and a metric carat is exactly 200 milligrams.
Formula
carats = zeptograms × 5e-21
This factor comes from each unit's defined relationship to the category's base unit: 1 zeptogram equals 1e-24 base units, and 1 carat equals 0.0002 base units, so dividing one by the other gives the direct zeptogram-to-carat factor of 5e-21.
Simple example
1 zg × 5e-21 = 5e-21 ct
1 zeptogram = 5e-21 carats.
Real-world example
50 zg × 5e-21 = 2.5e-19 ct
50 zeptograms = 2.5e-19 carats.
Conversion table
| Zeptogram (zg) | Carat (ct) |
|---|---|
| 1 zg | 5e-21 ct |
| 5 zg | 2.5e-20 ct |
| 10 zg | 5e-20 ct |
| 25 zg | 1.25e-19 ct |
| 50 zg | 2.5e-19 ct |
| 100 zg | 5e-19 ct |
Reverse conversion: Carat to Zeptogram
5e-21 ct × 2e+20 = 1 zg
5e-21 carats = 1 zeptogram.
zeptograms = carats × 2e+20
For a page dedicated to this direction, see Carat to Zeptogram.
Understanding the Zeptogram (zg)
Zeptogram is 1e-21 gram units.
Understanding the Carat (ct)
A metric carat is exactly 200 milligrams.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many carats are in 1 zeptogram?
1 zeptogram equals 5e-21 carats, using the exact defined conversion factor rather than an estimate.
How do I convert zeptogram to carat?
Multiply the zeptogram value by 5e-21. The converter above does this instantly to whatever precision you set.
How do I convert carat back to zeptogram?
Use the reverse factor: 1 carat equals 2e+20 zeptograms. You can also use the swap control in the converter above to flip the direction instantly.
What is a zeptogram?
Zeptogram (zg) is a unit of mass/weight.
What is a carat?
Carat (ct) is a unit of mass/weight.
Is the zeptogram to carat conversion exact?
Yes. Both zeptogram and carat are defined by fixed standards rather than physical artifacts, so the factor of 5e-21 used above is exact to as many digits as you choose to display.