Mass per volume density.
Grains per Cup to Stones per Teaspoon Converter — gr/cup to st/tsp
Convert Grain per Cup (gr/cup) to Stone per Teaspoon (st/tsp) using the exact conversion factor (1 grain per cup = 2.12585e-7 stone per teaspoon). See the formula, worked examples, and conversion table.
Grains per Cup to Stones 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 0.2738889767 / 1.28837375e+6.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Grains per Cup to Stones per Teaspoon
Grain per Cup and Stone 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
stones per teaspoon = grains per cup × 2.12585e-7
This factor comes from each unit's defined relationship to the category's base unit: 1 grain per cup equals 0.273888976724 base units, and 1 stone per teaspoon equals 1288373.74651 base units, so dividing one by the other gives the direct grain per cup-to-stone per teaspoon factor of 2.12585e-7.
Simple example
1 gr/cup × 2.12585e-7 = 2.12585e-7 st/tsp
1 grain per cup = 2.12585e-7 stones per teaspoon.
Real-world example
1,000 gr/cup × 2.12585e-7 = 0.000212585 st/tsp
1,000 grains per cup = 0.000212585 stones per teaspoon.
Conversion table
| Grain per Cup (gr/cup) | Stone per Teaspoon (st/tsp) |
|---|---|
| 0.1 gr/cup | 2.12585e-8 st/tsp |
| 1 gr/cup | 2.12585e-7 st/tsp |
| 10 gr/cup | 0.0000021259 st/tsp |
| 100 gr/cup | 0.0000212585 st/tsp |
| 1,000 gr/cup | 0.000212585 st/tsp |
| 10,000 gr/cup | 0.0021258503 st/tsp |
Reverse conversion: Stone per Teaspoon to Grain per Cup
2.12585e-7 st/tsp × 4704000 = 0.99999984 gr/cup
2.12585e-7 stones per teaspoon = 0.99999984 grains per cup.
grains per cup = stones per teaspoon × 4704000
For a page dedicated to this direction, see Stone per Teaspoon to Grain per Cup.
Understanding the Grain per Cup (gr/cup)
Mass per volume density.
Understanding the Stone per Teaspoon (st/tsp)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many stones per teaspoon are in 1 grain per cup?
1 grain per cup equals 2.12585e-7 stones per teaspoon, using the exact defined conversion factor rather than an estimate.
How do I convert grain per cup to stone per teaspoon?
Multiply the grain per cup value by 2.12585e-7. The converter above does this instantly to whatever precision you set.
How do I convert stone per teaspoon back to grain per cup?
Use the reverse factor: 1 stone per teaspoon equals 4,704,000 grains per cup. You can also use the swap control in the converter above to flip the direction instantly.
What is a grain per cup?
Grain per Cup (gr/cup) is a unit of density.
What is a stone per teaspoon?
Stone per Teaspoon (st/tsp) is a unit of density.
Is the grain per cup to stone per teaspoon conversion exact?
Yes. Both grain per cup and stone per teaspoon are defined by fixed standards rather than physical artifacts, so the factor of 2.12585e-7 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.