Mass per volume density.
Stones per Cubic foot to Grains per Cup Converter — st/ft3 to gr/cup
Convert Stone per Cubic foot (st/ft3) to Grain per Cup (gr/cup) using the exact conversion factor (1 stone per cubic foot = 818.7934028 grain per cup). See the formula, worked examples, and conversion table.
Stones per Cubic foot to Grains 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 224.2584872 / 0.2738889767.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Stones per Cubic foot to Grains per Cup
Stone per Cubic foot and Grain 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
grains per cup = stones per cubic foot × 818.793402778
This factor comes from each unit's defined relationship to the category's base unit: 1 stone per cubic foot equals 224.258487235 base units, and 1 grain per cup equals 0.273888976724 base units, so dividing one by the other gives the direct stone per cubic foot-to-grain per cup factor of 818.793402778.
Simple example
1 st/ft3 × 818.7934028 = 818.7934028 gr/cup
1 stone per cubic foot = 818.7934028 grains per cup.
Real-world example
1,000 st/ft3 × 818.7934028 = 818,793.4028 gr/cup
1,000 stones per cubic foot = 818,793.4028 grains per cup.
Conversion table
| Stone per Cubic foot (st/ft3) | Grain per Cup (gr/cup) |
|---|---|
| 0.1 st/ft3 | 81.87934028 gr/cup |
| 1 st/ft3 | 818.7934028 gr/cup |
| 10 st/ft3 | 8,187.934028 gr/cup |
| 100 st/ft3 | 81,879.34028 gr/cup |
| 1,000 st/ft3 | 818,793.4028 gr/cup |
| 10,000 st/ft3 | 8,187,934.028 gr/cup |
Reverse conversion: Grain per Cup to Stone per Cubic foot
818.7934028 gr/cup × 0.001221309303 = 1 st/ft3
818.7934028 grains per cup = 1 stones per cubic foot.
stones per cubic foot = grains per cup × 0.00122130930294
For a page dedicated to this direction, see Grain per Cup to Stone per Cubic foot.
Understanding the Stone per Cubic foot (st/ft3)
Mass per volume density.
Understanding the Grain per Cup (gr/cup)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grains per cup are in 1 stone per cubic foot?
1 stone per cubic foot equals 818.7934028 grains per cup, using the exact defined conversion factor rather than an estimate.
How do I convert stone per cubic foot to grain per cup?
Multiply the stone per cubic foot value by 818.7934028. The converter above does this instantly to whatever precision you set.
How do I convert grain per cup back to stone per cubic foot?
Use the reverse factor: 1 grain per cup equals 0.0012213093 stones per cubic foot. You can also use the swap control in the converter above to flip the direction instantly.
What is a stone per cubic foot?
Stone per Cubic foot (st/ft3) is a unit of density.
What is a grain per cup?
Grain per Cup (gr/cup) is a unit of density.
Is the stone per cubic foot to grain per cup conversion exact?
Yes. Both stone per cubic foot and grain per cup are defined by fixed standards rather than physical artifacts, so the factor of 818.7934028 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.