What is the 27 rule for stairs?

There isn't a widely recognized stair measurement rule based on 27 inches in furniture or building guides. Code minimums typically require at least 36 inches of stair width, though usable clear width often ends up closer to 28 to 31 inches after handrails.

What is the "4-inch rule" for sofas?

There's no standard "4-inch rule" documented in building or furniture-moving guides. The closer, verifiable figure is that handrails and brackets typically reduce a stairway's usable clear width by 3 to 5 inches, which is likely the source of similar-sounding rules of thumb.

What is the 2 2 1 rule for sofas?

This isn't a documented measurement standard for sofas or stairs. Rather than rely on an unverified rule, measure your own four decisive numbers directly: stair clear width, ceiling clearance, landing depth and width, and your sofa's diagonal depth.

What is the 2/3 rule for sofas?

No established "2/3 rule" appears in furniture-fit or stair-measurement guides. The reliable approach stays the same regardless: compare your sofa's diagonal depth against your landing depth and stair clear width rather than applying a fixed ratio.

How much landing depth does a sofa need to turn a corner?

As a rough guide, an 84 inch sofa often needs around 40 inches of landing depth to complete a 90 degree pivot. Shorter sofas generally need proportionally less, but it's worth confirming with a cardboard mockup before you rely on the estimate.

Movers pivoting a sofa around a stair landing

October 14, 2026 Dean P.

Sofa Fit: Calculate Stair Clearance, Then Mock Up the Turn

Filed in: en, measure stairs for sofa

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