Mass per volume density.
Pounds per Cubic foot to Grains per Fluid ounce Converter — lb/ft3 to gr/fl oz
Convert Pound per Cubic foot (lb/ft3) to Grain per Fluid ounce (gr/fl oz) using the exact conversion factor (1 pound per cubic foot = 7.310655382 grain per fluid ounce). See the formula, worked examples, conversion table, and common uses.
Pounds per Cubic foot to Grains per Fluid ounce 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 16.01846337 / 2.191111814.
Density uses kilograms per cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Pounds per Cubic foot to Grains per Fluid ounce
Pound per Cubic foot and Grain per Fluid ounce 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. Pound per Cubic foot is most often used for us construction material density specs (concrete, soil, lumber, insulation).
Formula
grains per fluid ounce = pounds per cubic foot × 7.31065538194
This factor comes from each unit's defined relationship to the category's base unit: 1 pound per cubic foot equals 16.018463374 base units, and 1 grain per fluid ounce equals 2.19111181379 base units, so dividing one by the other gives the direct pound per cubic foot-to-grain per fluid ounce factor of 7.31065538194.
Simple example
1 lb/ft3 × 7.310655382 = 7.310655382 gr/fl oz
1 pound per cubic foot = 7.310655382 grains per fluid ounce.
Real-world example
1,000 lb/ft3 × 7.310655382 = 7,310.655382 gr/fl oz
1,000 pounds per cubic foot = 7,310.655382 grains per fluid ounce.
Conversion table
| Pound per Cubic foot (lb/ft3) | Grain per Fluid ounce (gr/fl oz) |
|---|---|
| 0.1 lb/ft3 | 0.7310655382 gr/fl oz |
| 1 lb/ft3 | 7.310655382 gr/fl oz |
| 10 lb/ft3 | 73.10655382 gr/fl oz |
| 100 lb/ft3 | 731.0655382 gr/fl oz |
| 1,000 lb/ft3 | 7,310.655382 gr/fl oz |
| 10,000 lb/ft3 | 73,106.55382 gr/fl oz |
Reverse conversion: Grain per Fluid ounce to Pound per Cubic foot
7.310655382 gr/fl oz × 0.1367866419 = 1 lb/ft3
7.310655382 grains per fluid ounce = 1 pounds per cubic foot.
pounds per cubic foot = grains per fluid ounce × 0.136786641929
For a page dedicated to this direction, see Grain per Fluid ounce to Pound per Cubic foot.
Understanding the Pound per Cubic foot
Pound per Cubic foot (lb/ft3) measures density. The US customary unit for expressing density, commonly used in construction and engineering material specifications. It is classified as a US customary density unit.
Where it's used: United States (construction, engineering, materials specifications)
Uses of the Pound per Cubic foot today
- US construction material density specs (concrete, soil, lumber, insulation)
- US engineering material property tables
- Bulk material handling and shipping weight estimates
Understanding the Grain per Fluid ounce (gr/fl oz)
Mass per volume density.
Pound per Cubic foot — sources
- NIST Handbook 44 — General tables of units including US customary density measures.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grains per fluid ounce are in 1 pound per cubic foot?
1 pound per cubic foot equals 7.310655382 grains per fluid ounce, using the exact defined conversion factor rather than an estimate.
How do I convert pound per cubic foot to grain per fluid ounce?
Multiply the pound per cubic foot value by 7.310655382. The converter above does this instantly to whatever precision you set.
How do I convert grain per fluid ounce back to pound per cubic foot?
Use the reverse factor: 1 grain per fluid ounce equals 0.1367866419 pounds per cubic foot. You can also use the swap control in the converter above to flip the direction instantly.
What is a pound per cubic foot?
Pound per Cubic foot (lb/ft3) measures density. The US customary unit for expressing density, commonly used in construction and engineering material specifications. It is classified as a US customary density unit.
What is a grain per fluid ounce?
Grain per Fluid ounce (gr/fl oz) is a unit of density.
Is the pound per cubic foot to grain per fluid ounce conversion exact?
Yes. Both pound per cubic foot and grain per fluid ounce are defined by fixed standards rather than physical artifacts, so the factor of 7.310655382 used above is exact to as many digits as you choose to display.
Where is the pound per cubic foot still used today?
United States (construction, engineering, materials specifications)
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.