Mass per volume density.
Stone per Cubic inches to Carats per Cup Converter — st/in3 to ct/cup
Convert Stone per Cubic inch (st/in3) to Carat per Cup (ct/cup) using the exact conversion factor (1 stone per cubic inch = 458,411.7889 carat per cup). See the formula, worked examples, and conversion table.
Stone per Cubic inches to Carats per Cup converter
Converter
Density Converter
Convert thousands of mass-per-volume density combinations for science, engineering, agriculture, and fluids.
Context values
Some unit families need one extra value for a physically accurate result.
Mass per volume density.
Result = input x 387518.6659 / 0.8453505675.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Stone per Cubic inches to Carats per Cup
Stone per Cubic inch and Carat per Cup both measure density — mass per unit volume — a property used to identify materials, check manufacturing quality, and predict whether something floats or sinks. As a fixed reference point, water has a density of exactly 1000 kg/m³ (1 g/cm³, 1 g/mL) at its temperature of maximum density, which is why many density figures in science and engineering are quoted relative to water. Both are mass per volume density units.
Formula
carats per cup = stone per cubic inches × 458411.788931
This factor comes from each unit's defined relationship to the category's base unit: 1 stone per cubic inch equals 387518.665943 base units, and 1 carat per cup equals 0.845350567546 base units, so dividing one by the other gives the direct stone per cubic inch-to-carat per cup factor of 458411.788931.
Simple example
1 st/in3 × 458411.7889 = 458,411.7889 ct/cup
1 stone per cubic inch = 458,411.7889 carats per cup.
Real-world example
1,000 st/in3 × 458411.7889 = 458,411,788.9 ct/cup
1,000 stone per cubic inches = 458,411,788.9 carats per cup.
Conversion table
| Stone per Cubic inch (st/in3) | Carat per Cup (ct/cup) |
|---|---|
| 0.1 st/in3 | 45,841.17889 ct/cup |
| 1 st/in3 | 458,411.7889 ct/cup |
| 10 st/in3 | 4,584,117.889 ct/cup |
| 100 st/in3 | 45,841,178.89 ct/cup |
| 1,000 st/in3 | 458,411,788.9 ct/cup |
| 10,000 st/in3 | 4,584,117,889 ct/cup |
Reverse conversion: Carat per Cup to Stone per Cubic inch
1 ct/cup × 0.000002181444771 = 0.0000021814 st/in3
1 carat per cup = 0.0000021814 stone per cubic inches.
stone per cubic inches = carats per cup × 0.00000218144477116
For a page dedicated to this direction, see Carat per Cup to Stone per Cubic inch.
Understanding the Stone per Cubic inch (st/in3)
Mass per volume density.
Understanding the Carat per Cup (ct/cup)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many carats per cup are in 1 stone per cubic inch?
1 stone per cubic inch equals 458,411.7889 carats per cup, using the exact defined conversion factor rather than an estimate.
How do I convert stone per cubic inch to carat per cup?
Multiply the stone per cubic inch value by 458411.7889. The converter above does this instantly to whatever precision you set.
How do I convert carat per cup back to stone per cubic inch?
Use the reverse factor: 1 carat per cup equals 0.0000021814 stone per cubic inches. You can also use the swap control in the converter above to flip the direction instantly.
What is a stone per cubic inch?
Stone per Cubic inch (st/in3) is a unit of density.
What is a carat per cup?
Carat per Cup (ct/cup) is a unit of density.
Is the stone per cubic inch to carat per cup conversion exact?
Yes. Both stone per cubic inch and carat per cup are defined by fixed standards rather than physical artifacts, so the factor of 458411.7889 used above is exact to as many digits as you choose to display.
What's the difference between density and mass concentration?
Density is the mass of a pure substance or material per unit volume. Mass concentration is the mass of one component — like a dissolved solute — within a mixture's total volume. The two use the same kind of units but describe different physical situations.