Convert a wind speed in mph to a pressure in psf. The ASCE 7-22 velocity pressure is q = 0.00256·V², so a 150 mph wind carries about 57.6 psf. See the full conversion table below — then get the enforceable design pressure, with the site and surface coefficients applied.
The pressure a moving airstream carries scales with the square of its speed. In ASCE 7-22 units — miles per hour in, pounds per square foot out — that relationship has a single constant.
q = 0.00256 · V²
q is the velocity (stagnation) pressure in psf; V is the wind speed in mph. So a 150 mph wind carries 0.00256 × 150² ≈ 57.6 psf. That is the raw push — the starting point for a code design pressure, not the end of it.
Velocity pressure q = 0.00256·V² at each design speed. Round wind speed up to the nearest 5 mph before you read a code value.
Values are the raw velocity pressure. Your enforceable design pressure is higher or lower once exposure, height, gust, and the surface coefficients are applied — see below.
The table gives the wind’s raw energy. ASCE 7-22 then corrects it for where the building sits and what part of it you are designing. Three factors turn a speed into a stamped pressure.
q = 0.00256·V² is the stagnation pressure of the airstream at that speed. It assumes standard conditions and says nothing yet about your building.
The full ASCE 7-22 velocity pressure is qz = 0.00256·Kz·Kzt·Kd·Ke·V². Exposure and height (Kz), hills (Kzt), directionality (Kd), and elevation (Ke) move the raw number up or down.
A design pressure is p = qz(GCp − GCpi). A roof corner sees far more suction than a mid-wall panel at the same wind speed — the coefficients, not the speed, make that difference.
The raw conversion is one line; the enforceable pressure is a short procedure. Both live in the same calculator.
Read the raw pressure off the table, then run the wind load pressure calculator to get the code value with the coefficients applied.
Enter a ZIP and the mapped ASCE 7-22 design wind speed is looked up for you — no map tracing, no guessing the category.
See every factor built up in order in the how to calculate wind load guide.
Square the speed and multiply by 0.00256: q = 0.00256·V², with V in mph and q in psf. That gives the velocity (stagnation) pressure. A code design pressure then multiplies by the exposure, topographic, directionality, and elevation factors and the surface coefficients.
About 57.6 psf of raw velocity pressure: 0.00256 × 150². The design pressure on an actual surface can be well above or below that once exposure, height, gust, and the GCp for the zone are applied.
It bundles air density and the unit conversions so that speed in mph and pressure in psf line up. It is the standard coefficient in the ASCE 7-22 velocity pressure equation for sea-level air.
Because that formula is only the raw airstream pressure. ASCE 7-22 adjusts it with Kz, Kzt, Kd, and Ke, then applies GCp and GCpi for the surface. A roof corner and a mid-wall panel land on very different pressures at the same wind speed.
Yes, rearrange it: V = √(q / 0.00256). It returns the speed that produces a given raw velocity pressure — but a design pressure in psf includes coefficients, so it does not convert straight back to a wind speed.
Yes. The constant and the velocity pressure equation are ASCE 7-22 — the standard adopted through the Florida Building Code 8th Edition and by most of the country. Our calculators apply it end to end.
The table gives you the raw psf in a glance; the wind load pressure calculator gives you the enforceable design pressure with every coefficient applied and cited. Start free.
Walk every factor from risk category to psf in the how to calculate wind load guide, then run your own numbers.
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