Mass per volume density.
Stones per Cup to Carats per Teaspoon Converter — st/cup to ct/tsp
Convert Stone per Cup (st/cup) to Carat per Teaspoon (ct/tsp) using the exact conversion factor (1 stone per cup = 661.4888729 carat per teaspoon). See the formula, worked examples, and conversion table.
Stones per Cup to Carats per Teaspoon 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 26841.11972 / 40.57682724.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Stones per Cup to Carats per Teaspoon
Stone per Cup and Carat per Teaspoon 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 teaspoon = stones per cup × 661.488872917
This factor comes from each unit's defined relationship to the category's base unit: 1 stone per cup equals 26841.119719 base units, and 1 carat per teaspoon equals 40.5768272422 base units, so dividing one by the other gives the direct stone per cup-to-carat per teaspoon factor of 661.488872917.
Simple example
1 st/cup × 661.4888729 = 661.4888729 ct/tsp
1 stone per cup = 661.4888729 carats per teaspoon.
Real-world example
1,000 st/cup × 661.4888729 = 661,488.8729 ct/tsp
1,000 stones per cup = 661,488.8729 carats per teaspoon.
Conversion table
| Stone per Cup (st/cup) | Carat per Teaspoon (ct/tsp) |
|---|---|
| 0.1 st/cup | 66.14888729 ct/tsp |
| 1 st/cup | 661.4888729 ct/tsp |
| 10 st/cup | 6,614.888729 ct/tsp |
| 100 st/cup | 66,148.88729 ct/tsp |
| 1,000 st/cup | 661,488.8729 ct/tsp |
| 10,000 st/cup | 6,614,888.729 ct/tsp |
Reverse conversion: Carat per Teaspoon to Stone per Cup
661.4888729 ct/tsp × 0.001511741226 = 1 st/cup
661.4888729 carats per teaspoon = 1 stones per cup.
stones per cup = carats per teaspoon × 0.00151174122641
For a page dedicated to this direction, see Carat per Teaspoon to Stone per Cup.
Understanding the Stone per Cup (st/cup)
Mass per volume density.
Understanding the Carat per Teaspoon (ct/tsp)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many carats per teaspoon are in 1 stone per cup?
1 stone per cup equals 661.4888729 carats per teaspoon, using the exact defined conversion factor rather than an estimate.
How do I convert stone per cup to carat per teaspoon?
Multiply the stone per cup value by 661.4888729. The converter above does this instantly to whatever precision you set.
How do I convert carat per teaspoon back to stone per cup?
Use the reverse factor: 1 carat per teaspoon equals 0.0015117412 stones per cup. You can also use the swap control in the converter above to flip the direction instantly.
What is a stone per cup?
Stone per Cup (st/cup) is a unit of density.
What is a carat per teaspoon?
Carat per Teaspoon (ct/tsp) is a unit of density.
Is the stone per cup to carat per teaspoon conversion exact?
Yes. Both stone per cup and carat per teaspoon are defined by fixed standards rather than physical artifacts, so the factor of 661.4888729 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.