psf to PSI Converter
Enter the pressure in psf below to convert it to psi.
Convert psf to PSI
Enter a value in psf (psf) to convert to psi (psi).
Pounds per Square Foot to Pounds per Square Inch Conversion Table
Table showing various pounds per square foot measurements converted to psi. Click any preset value or arrow to load it into the converter.
| psf (psf) | PSI (psi) |
|---|---|
| 1 psf | 0.0069444 psi |
| 2 psf | 0.0138889 psi |
| 2.5 psf | 0.0173611 psi |
| 5 psf | 0.0347222 psi |
| 10 psf | 0.0694444 psi |
| 15 psf | 0.1041667 psi |
| 20 psf | 0.1388889 psi |
| 25 psf | 0.1736111 psi |
| 30 psf | 0.2083333 psi |
| 50 psf | 0.3472222 psi |
How to Convert psf to PSI
To convert psf to psi, multiply the pressure by the following conversion ratio: 0.0069444 psi/pounds per square foot.
Since one pounds per square foot is equal to 0.0069444 psi, you can use this simple formula to convert:
The pressure in psi is equal to the pressure in psf multiplied by 0.0069444.
For example, here's how to convert 5 psf to psi using the formula above.
How Many PSI Are in a Pounds per Square Foot?
There are 0.0069444 psi in a pounds per square foot, which is why we use this value in the formula above.
Our pounds per square foot to pounds per square inch calculator automatically converts your pressure measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
psf and psi are both units used to measure pressure. Keep reading to learn more about each unit.
What Is a Pounds per Square Foot?
A pounds per square foot is a unit of pressure equal to 47.880259 pascals (Pa), the base unit for pressure. Equal to 1/144 PSI (47.88 Pascals), used in aerodynamic and structural wind loading. [1]
The pounds per square foot is classified as a US customary and imperial unit of pressure. psf can be abbreviated as psf; for example, 1 pounds per square foot can be written as 1 psf.
When working with psf (psf) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, psf (psf) are widely used across standard pressure applications within US customary and imperial workflows, engineering documentation, and technical data sheets.
What Is a Pounds per Square Inch?
A pounds per square inch is a unit of pressure equal to 6,894.7572932 pascals (Pa), the base unit for pressure. Imperial & US pressure unit equal to 1 pound-force per square inch (6.89476 kPa). [2]
The pounds per square inch is classified as a US customary and imperial unit of pressure. PSI can be abbreviated as psi; for example, 1 pounds per square inch can be written as 1 psi.
When working with psi (psi) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, psi (psi) are widely used across large-scale industrial, bulk, and macro-level pressure specifications within US customary and imperial workflows, engineering documentation, and technical data sheets.
When converting pressure between psf (psf) and psi (psi), keep full floating-point precision (1 psf = 0.0069444 psi; 1 psi = 144 psf) during intermediate calculations and round only the final pounds per square inch figure to match your instrument tolerance.
More Pounds per Square Foot & Pounds per Square Inch Conversions
Need to calculate in the opposite direction? Use our psi to psf calculator to switch your starting unit immediately. You can also explore related tools such as converting psi to psf, converting bars to psi, or converting kilopascals to psi.
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Pressure & Stress))·Pressure Metrology Standard — psf (psf) to PSI (psi)
- [2]NIST CUU SpecificationNIST CUU (Derived SI Unit: Pascal (Pa))·Unit Specifications: Pounds per Square Foot (psf) (psf) & Pounds per Square Inch (psi)
- [3]BIPM ReferenceBIPM (SI Brochure (9th Ed.) — Mechanics)·Conversion Factors & Mathematical Basis (psf to psi)