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Rise × run

6.75″ rise × 11″ run stairs

What a 6.75-inch riser paired with a 11-inch tread actually gives you — pitch, comfort, and code status — plus the calculator to size a full flight.

Pitch
31.5°
Blondel 2R+T
24.5in
Comfort
Ideal

Code status

A 6.75-inch riser with a 11-inch tread is compliant under IRC 2021 (max riser 7.75″, min tread 10.0″), and compliant under the IBC commercial standard (max riser 7.0″, min tread 11.0″).

The numbers

pitch = atan(6.75 / 11) = 31.5°
Blondel = 2 × 6.75 + 11 = 24.5″ (ideal ≈ 24–25)

This pair is one step's geometry. To size a complete flight for your floor-to-floor height, enter your total rise in the calculator and it will hold the riser near 6.75″ while checking every code limit.

Size a full flight

What this combination is like to use

A 6.75-inch riser with a 11-inch tread produces a 31.5-degree pitch, which is squarely in the comfortable range for a staircase. In practice that means it is a natural everyday rhythm that suits a main staircase. Its Blondel value of 24.5 inches lands right in the 24–25 inch Blondel comfort band, so it should feel natural underfoot.

Across a typical flight of about 14 treads, the 11-inch tread depth works out to roughly 11.9 feet of horizontal run — a moderate footprint. This pairing clears both the residential IRC and the stricter commercial IBC, which makes it unusually versatile — usable in a home or a light-commercial setting without redesign.

When to choose it

Pick this pairing when comfort and easy access matter more than saving floor area — it is a good main-stair choice in a home with the space to accommodate the longer run. Whatever your floor-to-floor height, the calculator below will hold the riser near 6.75 inches, divide the rise into uniform steps, and check the result against the code you select.

Nearby combinations

8.25″ × 9″, 7.5″ × 9.5″, 7.5″ × 10.5″