Mass per volume density.
Carats per Cup to Stones per Cubic Millimeter Converter — ct/cup to st/mm3
Convert Carat per Cup (ct/cup) to Stone per Cubic Millimeter (st/mm3) using the exact conversion factor (1 carat per cup = 1.331199e-10 stone per cubic millimeter). See the formula, worked examples, and conversion table.
Carats per Cup to Stones per Cubic Millimeter 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 0.8453505675 / 6.35029318e+9.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Carats per Cup to Stones per Cubic Millimeter
Carat per Cup and Stone per Cubic Millimeter 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
stones per cubic millimeter = carats per cup × 1.331199e-10
This factor comes from each unit's defined relationship to the category's base unit: 1 carat per cup equals 0.845350567546 base units, and 1 stone per cubic millimeter equals 6350293180 base units, so dividing one by the other gives the direct carat per cup-to-stone per cubic millimeter factor of 1.331199e-10.
Simple example
1 ct/cup × 1.331199e-10 = 1.331199e-10 st/mm3
1 carat per cup = 1.331199e-10 stones per cubic millimeter.
Real-world example
1,000 ct/cup × 1.331199e-10 = 1.331199e-7 st/mm3
1,000 carats per cup = 1.331199e-7 stones per cubic millimeter.
Conversion table
| Carat per Cup (ct/cup) | Stone per Cubic Millimeter (st/mm3) |
|---|---|
| 0.1 ct/cup | 1.331199e-11 st/mm3 |
| 1 ct/cup | 1.331199e-10 st/mm3 |
| 10 ct/cup | 1.331199e-9 st/mm3 |
| 100 ct/cup | 1.331199e-8 st/mm3 |
| 1,000 ct/cup | 1.331199e-7 st/mm3 |
| 10,000 ct/cup | 0.0000013312 st/mm3 |
Reverse conversion: Stone per Cubic Millimeter to Carat per Cup
1.331199e-10 st/mm3 × 7512023324 = 0.9999997936 ct/cup
1.331199e-10 stones per cubic millimeter = 0.9999997936 carats per cup.
carats per cup = stones per cubic millimeter × 7512023323.57
For a page dedicated to this direction, see Stone per Cubic Millimeter to Carat per Cup.
Understanding the Carat per Cup (ct/cup)
Mass per volume density.
Understanding the Stone per Cubic Millimeter (st/mm3)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many stones per cubic millimeter are in 1 carat per cup?
1 carat per cup equals 1.331199e-10 stones per cubic millimeter, using the exact defined conversion factor rather than an estimate.
How do I convert carat per cup to stone per cubic millimeter?
Multiply the carat per cup value by 1.331199e-10. The converter above does this instantly to whatever precision you set.
How do I convert stone per cubic millimeter back to carat per cup?
Use the reverse factor: 1 stone per cubic millimeter equals 7,512,023,324 carats per cup. You can also use the swap control in the converter above to flip the direction instantly.
What is a carat per cup?
Carat per Cup (ct/cup) is a unit of density.
What is a stone per cubic millimeter?
Stone per Cubic Millimeter (st/mm3) is a unit of density.
Is the carat per cup to stone per cubic millimeter conversion exact?
Yes. Both carat per cup and stone per cubic millimeter are defined by fixed standards rather than physical artifacts, so the factor of 1.331199e-10 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.