This converter turns pounds per cubic inch into pounds per cubic foot instantly, using the exact factor 1 pound per cubic inch = 1728 pounds per cubic foot. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
Used for metals and dense engineering materials. The US construction unit for concrete, soil and timber density.
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 inch- The amount you are converting, measured in pounds per cubic inch
1728- The exact number of pounds per cubic foot in one pound per cubic inch
pounds per cubic foot- The converted result
How it works, step by step
- Enter the number of pounds per cubic inch you want to convert.
- The value is multiplied by 1728, the exact conversion factor.
- The result is displayed in pounds per cubic foot, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 pounds per cubic inch
Multiply 5 by 1728. That gives 8,640 pounds per cubic foot. A quick sanity check: one pound per cubic inch is larger than one pound per cubic foot, so the number should get bigger — and it does.
Converting 72 pounds per cubic inch
72 × 1728 = 124,416 pounds per cubic foot. Working backwards, 124,416 ÷ 1728 returns 72 pounds per cubic inch, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many pounds per cubic foot are in one pound per cubic inch?
Exactly 1728. 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 inch to pounds per cubic foot?
Pounds Per Cubic Foot = pounds per cubic inch × 1728. To reverse it, divide instead: pounds per cubic inch = pounds per cubic foot ÷ 1728, which is the same as multiplying by 0.0005787037037.
Is the pound per cubic inch bigger than the pound per cubic foot?
Yes. One pound per cubic inch equals 1728 pounds per cubic foot, so it is the larger unit.
Why does my answer differ slightly from other lb-in3 to lb-ft3 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 inch?
Used for metals and dense engineering materials.
What is a pound per cubic foot?
The US construction unit for concrete, soil and timber density.
Pounds Per Cubic Inch to pounds per cubic foot reference table
| Pounds Per Cubic Inch | Pounds Per Cubic Foot |
|---|---|
| 0.5 lb/in³ | 864 lb/ft³ |
| 1 lb/in³ | 1,728 lb/ft³ |
| 2 lb/in³ | 3,456 lb/ft³ |
| 3 lb/in³ | 5,184 lb/ft³ |
| 5 lb/in³ | 8,640 lb/ft³ |
| 10 lb/in³ | 17,280 lb/ft³ |
| 15 lb/in³ | 25,920 lb/ft³ |
| 20 lb/in³ | 34,560 lb/ft³ |
| 25 lb/in³ | 43,200 lb/ft³ |
| 50 lb/in³ | 86,400 lb/ft³ |
| 75 lb/in³ | 129,600 lb/ft³ |
| 100 lb/in³ | 172,800 lb/ft³ |
| 250 lb/in³ | 432,000 lb/ft³ |
| 500 lb/in³ | 864,000 lb/ft³ |
| 1000 lb/in³ | 1,728,000 lb/ft³ |
Exact factor: 1 pound per cubic inch = 1728 pounds per cubic foot. Values rounded for display.