This converter turns pounds per cubic foot into pounds per US gallon instantly, using the exact factor 1 pound per cubic foot = 0.1336805556 pounds per US gallon. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The US construction unit for concrete, soil and timber density. The drilling-mud and paint-industry density unit.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
pounds per cubic foot- The amount you are converting, measured in pounds per cubic foot
0.1336805556- The exact number of pounds per US gallon in one pound per cubic foot
pounds per US gallon- The converted result
How it works, step by step
- Enter the number of pounds per cubic foot you want to convert.
- The value is multiplied by 0.1336805556, the exact conversion factor.
- The result is displayed in pounds per US gallon, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 pounds per cubic foot
Multiply 5 by 0.13368056. That gives 0.668403 pounds per US gallon. A quick sanity check: one pound per cubic foot is smaller than one pound per US gallon, so the number should get smaller — and it does.
Converting 72 pounds per cubic foot
72 × 0.13368056 = 9.625 pounds per US gallon. Working backwards, 9.625 ÷ 0.13368056 returns 72 pounds per cubic foot, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many pounds per US gallon are in one pound per cubic foot?
Exactly 0.1336805556. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert pounds per cubic foot to pounds per US gallon?
Pounds Per Us Gallon = pounds per cubic foot × 0.1336805556. To reverse it, divide instead: pounds per cubic foot = pounds per US gallon ÷ 0.1336805556, which is the same as multiplying by 7.480519481.
Is the pound per cubic foot bigger than the pound per US gallon?
No. One pound per cubic foot is only 0.133681 of a pound per US gallon, so the pound per US gallon is the larger unit.
Why does my answer differ slightly from other lb-ft3 to lb-gal converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a pound per cubic foot?
The US construction unit for concrete, soil and timber density.
What is a pound per US gallon?
The drilling-mud and paint-industry density unit.
Pounds Per Cubic Foot to pounds per US gallon reference table
| Pounds Per Cubic Foot | Pounds Per Us Gallon |
|---|---|
| 0.5 lb/ft³ | 0.06684 lb/gal |
| 1 lb/ft³ | 0.133681 lb/gal |
| 2 lb/ft³ | 0.267361 lb/gal |
| 3 lb/ft³ | 0.401042 lb/gal |
| 5 lb/ft³ | 0.668403 lb/gal |
| 10 lb/ft³ | 1.3368 lb/gal |
| 15 lb/ft³ | 2.0052 lb/gal |
| 20 lb/ft³ | 2.6736 lb/gal |
| 25 lb/ft³ | 3.342 lb/gal |
| 50 lb/ft³ | 6.684 lb/gal |
| 75 lb/ft³ | 10.026 lb/gal |
| 100 lb/ft³ | 13.3681 lb/gal |
| 250 lb/ft³ | 33.4201 lb/gal |
| 500 lb/ft³ | 66.8403 lb/gal |
| 1000 lb/ft³ | 133.6806 lb/gal |
Exact factor: 1 pound per cubic foot = 0.1336805556 pounds per US gallon. Values rounded for display.