Tools
Wind Load PSF / MPH Converter
A free tool that converts between wind speed in mph and basic wind pressure in psf.
Wind load PSF / MPH converter
A 120 mph wind exerts about 36.9 psf of basic pressure.
Basic velocity pressure only. A door's required design pressure is higher once exposure, gust, and shape factors are applied. Confirm the rated design pressure with your AHJ and the manufacturer.
In plain terms
Wind speed and wind pressure are two ways of saying the same thing. Speed is how fast the air moves in mph. Pressure is how hard it pushes on your door in pounds per square foot. The faster the wind, the harder the push, and it climbs with the square of the speed, so doubling the speed roughly quadruples the push.
Rule of thumb: basic pressure is the speed in mph squared, times 0.00256. A 120 mph wind works out to about 37 psf of starting pressure.
What each part means
| Term | Plain meaning | Note |
|---|---|---|
| MPH | Ultimate design wind speed | from the code map for your site |
| PSF | Pounds per square foot of pressure | what the door must resist |
| 0.00256 | Air-density constant | turns speed into pressure |
| WindCode | Clopay rating tier W1 to W9 | higher tier resists more pressure |
A worked example
Worked example. A 120 mph design wind: 120 x 120 x 0.00256 = about 37 psf of basic pressure, which lands around a W7 tier. The door's required design pressure is higher once exposure and shape factors are added.
Related questions
Questions this tool answers
Short answers below, with a link to the full write-up on each.
What does PSF mean on a garage door wind rating, and how does it compare to MPH?
PSF means pounds per square foot, the engineering unit for wind pressure.
Read full answerWhat is Clopay WindCode and do I need it in Colorado?
WindCode is Clopay's wind-resistance rating system for garage doors, with levels W1 through W9 based on design pressure in pounds per square foot.
Read full answerWhat wind load rating does a garage door need in Colorado?
Most Front Range garage doors must meet the design wind pressure for their location, typically around 20 PSF for the Denver metro area based on a 90 mph ASCE 7-22 design wind speed.
Read full answerWhat is a WindCode rating on a garage door?
WindCode is Clopay's proprietary wind-resistance rating system for garage doors.
Read full answerReference & standards
The codes and standards behind it
The engineering sources this tool is built on.
- IRC R609.4.1 - Garage Door Wind Pressure Label RequirementsIRC R609.4.1 requires a permanent label on every installed garage door showing the manufacturer, model/series number, positive and negative design wind pressure ratings, the installation instruction drawing reference, and the test standard used.
- IBC Section 1609 - Wind Loads: The Commercial Building Code Basis for Garage Door Wind DesignIBC Section 1609 governs wind load design for commercial buildings, referencing ASCE 7-22 as the design standard.
- IRC R609.4 - Garage Door Structural Testing RequirementsIRC R609.4 requires that garage doors installed in the United States be tested to ASTM E330 or ANSI/DASMA 108 and meet the pass/fail criteria of ANSI/DASMA 108.
- DASMA TDS 177 - Applying the Kd Factor to Garage Door Wind Load CalculationsDASMA TDS 177 explains how the directionality factor Kd from ASCE 7 applies to garage door wind load calculations.
- IBC 1609.1.2 - Windborne Debris Regions: When Garage Doors Need Impact ProtectionIBC 1609.1.2 defines windborne debris regions and requires that glazed openings in those regions have impact-resistant protection.
- IBC 1609.2.2 - Glazed Garage Door Impact Protection in Windborne Debris RegionsIBC 1609.2.2 requires garage door glazed openings in windborne debris regions to meet ANSI/DASMA 115 or an approved impact standard.
- DASMA TDS 155 - Residential and Commercial Wind Load GuidesDASMA TDS 155 provides separate wind load selection guides for residential and commercial garage doors.
- DASMA TDS 168 - Wind Loads on Garage Doors FAQDASMA TDS 168 answers the most frequently asked questions about wind loads on garage doors, including how design pressure is determined, what the label on the door means, how psf ratings relate to mph wind speeds, and what to do if a door is not rated for the local design wind speed.
- DASMA TDS 194 - PSF versus MPH in Garage Door Wind SpecificationsDASMA TDS 194 explains the difference between miles per hour (mph) wind speed and pounds per square foot (psf) design pressure in garage door specifications.
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