To convert pounds per square foot to bar, multiply by 0.0004788025898. That factor is the whole relationship: both units measure pressure, so the conversion is a proportion with no offset and no substance-specific constant.
The unit US building codes give floor, roof and wind loads in. Almost exactly atmospheric pressure; standard in European industry and diving.
Gauge versus absolute. A tyre gauge reading 32 psi means 32 psi above atmospheric, which is about 46.7 psi absolute. Converting the number is straightforward; remembering which zero it was measured from is where the mistakes happen. N/mm² and MPa are the same size, so a drawing quoting either is quoting the same stress. Below the calculator there is a step table for the values people look up most, and a second table putting real pressure figures into bar so the number you get has something to be compared against.
The formula
pounds per square foot- The amount you are converting, in pounds per square foot
0.000478802589803- The exact number of bar in one pound per square foot
bar- The converted result
How it works, step by step
- Enter the value in pounds per square foot.
- It is multiplied by 0.000478802589803, the exact factor between the two units.
- The answer is shown in bar, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Blood pressure, systolic: 334 psf in bar
Take blood pressure, systolic, roughly 334 psf. The conversion is a single multiplication — 334 × 0.000478803 — giving 0.15992 bar. Because the relationship is proportional, doubling the input doubles the answer to 0.31984 bar.
A steam boiler: 2.09e+04 psf in bar
At 2.09e+04 psf (a steam boiler), the same quantity in bar is 2.09e+04 × 0.000478803 = 10.007 bar. One pound per square foot is 0.000478803 bar, so the numbers shrink as expected.
How to read your score
Frequently asked questions
How many bar are in one pound per square foot?
Exactly 0.000478802589803. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert pounds per square foot to bar?
bar = pounds per square foot × 0.000478802589803. Reversed, pounds per square foot = bar ÷ 0.000478802589803, which is the same as multiplying by 2088.54342332.
Which is the bigger unit, the pound per square foot or the bar?
The bar. One pound per square foot is only 0.000478803 of a bar, so it takes 2088.54 pounds per square foot to make one bar.
What does this quantity actually measure?
Both units measure pressure. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a pound per square foot?
The unit US building codes give floor, roof and wind loads in.
What is a bar?
Almost exactly atmospheric pressure; standard in European industry and diving.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do psf to bar in my head?
Plenty of people do this in their head: divide by 2100 instead of using the exact factor 0.0004788025898. At 100 that shortcut gives 0.047619048 bar, off by 0.0002612 bar or about 0.55%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Pounds Per Square Foot to bar reference tables
| Pounds Per Square Foot | Bar |
|---|---|
| 0.5 psf | 0.000239401 bar |
| 1 psf | 0.000478803 bar |
| 2 psf | 0.000957605 bar |
| 3 psf | 0.00143641 bar |
| 5 psf | 0.00239401 bar |
| 10 psf | 0.00478803 bar |
| 20 psf | 0.00957605 bar |
| 25 psf | 0.0119701 bar |
| 50 psf | 0.0239401 bar |
| 75 psf | 0.0359102 bar |
| 100 psf | 0.0478803 bar |
| 250 psf | 0.119701 bar |
| 500 psf | 0.239401 bar |
| 1000 psf | 0.478803 bar |
| 5000 psf | 2.39401 bar |
Exact factor: 1 pound per square foot = 0.000478802589803 bar.
| Quantity | psf | bar |
|---|---|---|
| Sea-level air | 2116 psf | 1.013 bar |
| A car tyre | 4608 psf | 2.206 bar |
| Blood pressure, systolic | 334.1 psf | 0.16 bar |
| A bicycle tyre | 1.296e+04 psf | 6.205 bar |
| A domestic water main | 8354 psf | 4 bar |
| A steam boiler | 2.089e+04 psf | 10 bar |
Published reference values, converted with the same factor this page uses.