Mass per volume density.
Ounces per Fluid ounce to Drams per Cup Converter — oz/fl oz to dr/cup
Convert Ounce per Fluid ounce (oz/fl oz) to Dram per Cup (dr/cup) using the exact conversion factor (1 ounce per fluid ounce = 128 dram per cup). See the formula, worked examples, and conversion table.
Ounces per Fluid ounce to Drams 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 958.6114185 / 7.489151707.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Ounces per Fluid ounce to Drams per Cup
Ounce per Fluid ounce and Dram 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
drams per cup = ounces per fluid ounce × 128
This factor comes from each unit's defined relationship to the category's base unit: 1 ounce per fluid ounce equals 958.611418535 base units, and 1 dram per cup equals 7.48915170731 base units, so dividing one by the other gives the direct ounce per fluid ounce-to-dram per cup factor of 128.
Simple example
1 oz/fl oz × 128 = 128 dr/cup
1 ounce per fluid ounce = 128 drams per cup.
Real-world example
1,000 oz/fl oz × 128 = 128,000 dr/cup
1,000 ounces per fluid ounce = 128,000 drams per cup.
Conversion table
| Ounce per Fluid ounce (oz/fl oz) | Dram per Cup (dr/cup) |
|---|---|
| 0.1 oz/fl oz | 12.8 dr/cup |
| 1 oz/fl oz | 128 dr/cup |
| 10 oz/fl oz | 1,280 dr/cup |
| 100 oz/fl oz | 12,800 dr/cup |
| 1,000 oz/fl oz | 128,000 dr/cup |
| 10,000 oz/fl oz | 1,280,000 dr/cup |
Reverse conversion: Dram per Cup to Ounce per Fluid ounce
128 dr/cup × 0.0078125 = 1 oz/fl oz
128 drams per cup = 1 ounce per fluid ounce.
ounces per fluid ounce = drams per cup × 0.0078125
For a page dedicated to this direction, see Dram per Cup to Ounce per Fluid ounce.
Understanding the Ounce per Fluid ounce (oz/fl oz)
Mass per volume density.
Understanding the Dram per Cup (dr/cup)
Mass per volume density.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many drams per cup are in 1 ounce per fluid ounce?
1 ounce per fluid ounce equals 128 drams per cup, using the exact defined conversion factor rather than an estimate.
How do I convert ounce per fluid ounce to dram per cup?
Multiply the ounce per fluid ounce value by 128. The converter above does this instantly to whatever precision you set.
How do I convert dram per cup back to ounce per fluid ounce?
Use the reverse factor: 1 dram per cup equals 0.0078125 ounces per fluid ounce. You can also use the swap control in the converter above to flip the direction instantly.
What is a ounce per fluid ounce?
Ounce per Fluid ounce (oz/fl oz) is a unit of density.
What is a dram per cup?
Dram per Cup (dr/cup) is a unit of density.
Is the ounce per fluid ounce to dram per cup conversion exact?
Yes. Both ounce per fluid ounce and dram per cup are defined by fixed standards rather than physical artifacts, so the factor of 128 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.