Mass per volume density.
Ounces per Teaspoon to Grains per Cup Converter — oz/tsp to gr/cup
Convert Ounce per Teaspoon (oz/tsp) to Grain per Cup (gr/cup) using the exact conversion factor (1 ounce per teaspoon = 21,000 grain per cup). See the formula, worked examples, and conversion table.
Ounces per Teaspoon 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 5751.668511 / 0.2738889767.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Ounces per Teaspoon to Grains per Cup
Ounce per Teaspoon 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 = ounces per teaspoon × 21000
This factor comes from each unit's defined relationship to the category's base unit: 1 ounce per teaspoon equals 5751.66851121 base units, and 1 grain per cup equals 0.273888976724 base units, so dividing one by the other gives the direct ounce per teaspoon-to-grain per cup factor of 21000.
Simple example
1 oz/tsp × 21000 = 21,000 gr/cup
1 ounce per teaspoon = 21,000 grains per cup.
Real-world example
1,000 oz/tsp × 21000 = 21,000,000 gr/cup
1,000 ounces per teaspoon = 21,000,000 grains per cup.
Conversion table
| Ounce per Teaspoon (oz/tsp) | Grain per Cup (gr/cup) |
|---|---|
| 0.1 oz/tsp | 2,100 gr/cup |
| 1 oz/tsp | 21,000 gr/cup |
| 10 oz/tsp | 210,000 gr/cup |
| 100 oz/tsp | 2,100,000 gr/cup |
| 1,000 oz/tsp | 21,000,000 gr/cup |
| 10,000 oz/tsp | 210,000,000 gr/cup |
Reverse conversion: Grain per Cup to Ounce per Teaspoon
1 gr/cup × 0.00004761904762 = 0.000047619 oz/tsp
1 grain per cup = 0.000047619 ounces per teaspoon.
ounces per teaspoon = grains per cup × 0.000047619047619
For a page dedicated to this direction, see Grain per Cup to Ounce per Teaspoon.
Understanding the Ounce per Teaspoon (oz/tsp)
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 ounce per teaspoon?
1 ounce per teaspoon equals 21,000 grains per cup, using the exact defined conversion factor rather than an estimate.
How do I convert ounce per teaspoon to grain per cup?
Multiply the ounce per teaspoon value by 21000. The converter above does this instantly to whatever precision you set.
How do I convert grain per cup back to ounce per teaspoon?
Use the reverse factor: 1 grain per cup equals 0.000047619 ounces per teaspoon. You can also use the swap control in the converter above to flip the direction instantly.
What is a ounce per teaspoon?
Ounce per Teaspoon (oz/tsp) is a unit of density.
What is a grain per cup?
Grain per Cup (gr/cup) is a unit of density.
Is the ounce per teaspoon to grain per cup conversion exact?
Yes. Both ounce per teaspoon and grain per cup are defined by fixed standards rather than physical artifacts, so the factor of 21000 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.