One atmosphere is exactly 2116.216624 pounds per square foot, so converting atmospheres to pounds per square foot is a single multiplication. Enter any figure and the result appears as you type — the arithmetic runs in your browser, so nothing is sent anywhere.
Standard atmospheric pressure by definition — 101,325 pascals exactly. The unit US building codes give floor, roof and wind loads in.
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. Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into pounds per square foot, which is usually more useful than the bare number.
The formula
atmospheres- The amount you are converting, in atmospheres
2116.21662367- The exact number of pounds per square foot in one atmosphere
pounds per square foot- The converted result
How it works, step by step
- Enter the value in atmospheres.
- It is multiplied by 2116.21662367, the exact factor between the two units.
- The answer is shown in pounds per square foot, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A bicycle tyre: 6.12 atm in pounds per square foot
Take a bicycle tyre, roughly 6.12 atm. The conversion is a single multiplication — 6.12 × 2116.22 — giving 12,951.2 psf. Because the relationship is proportional, doubling the input doubles the answer to 25,902.5 psf.
Sea-level air: 1 atm in pounds per square foot
Sea-level air comes to about 1 atm. Multiplying by the factor: 1 × 2116.22 = 2116.22 psf. Dividing the answer back by 2116.22 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
How to read your score
Frequently asked questions
How many pounds per square foot are in one atmosphere?
Exactly 2116.21662367. 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 atmospheres to pounds per square foot?
pounds per square foot = atmospheres × 2116.21662367. Reversed, atmospheres = pounds per square foot ÷ 2116.21662367, which is the same as multiplying by 0.000472541416041.
Which is the bigger unit, the atmosphere or the pound per square foot?
The atmosphere. One atmosphere equals 2116.22 pounds per square foot.
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 atmosphere?
Standard atmospheric pressure by definition — 101,325 pascals exactly.
What is a pound per square foot?
The unit US building codes give floor, roof and wind loads in.
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 atm to psf in my head?
Plenty of people do this in their head: multiply by 2100 instead of using the exact factor 2116.216624. At 100 that shortcut gives 210,000 pounds per square foot, off by 1622 pounds per square foot or about 0.77%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Atmospheres to pounds per square foot reference tables
| Atmospheres | Pounds Per Square Foot |
|---|---|
| 0.5 atm | 1058.11 psf |
| 1 atm | 2116.22 psf |
| 2 atm | 4232.43 psf |
| 3 atm | 6348.65 psf |
| 5 atm | 10,581.1 psf |
| 10 atm | 21,162.2 psf |
| 20 atm | 42,324.3 psf |
| 25 atm | 52,905.4 psf |
| 50 atm | 105,811 psf |
| 75 atm | 158,716 psf |
| 100 atm | 211,622 psf |
| 250 atm | 529,054 psf |
| 500 atm | 1.05811e+06 psf |
| 1000 atm | 2.11622e+06 psf |
| 5000 atm | 1.05811e+07 psf |
Exact factor: 1 atmosphere = 2116.21662367 pounds per square foot.
| Quantity | atm | psf |
|---|---|---|
| Sea-level air | 1 atm | 2116 psf |
| A car tyre | 2.177 atm | 4608 psf |
| Blood pressure, systolic | 0.1579 atm | 334.1 psf |
| A bicycle tyre | 6.124 atm | 1.296e+04 psf |
| A domestic water main | 3.948 atm | 8354 psf |
| A steam boiler | 9.869 atm | 2.089e+04 psf |
Published reference values, converted with the same factor this page uses.