Stair Tread Sizes: Standard Width, Depth, and Thickness

Standard Stair Tread Sizes at a Glance

Most residential stair treads run about 36 to 48 inches wide, about 10 to 11 inches deep, and about 1 to 1 1/4 inches thick. Some newer staircases are deeper, in the 12 to 14 inch range. These are typical sizes, not a rule, and every staircase in an older house is a little different.

The confusing part is the vocabulary. Shops, builders, and homeowners use width, depth, and length in different ways, so the same number can mean two things.

Width, Depth, and Thickness Explained

When a retailer lists a tread as 36 inches by 11 1/2 inches, the 36 is the width across the stair and the 11 1/2 is the depth. When someone asks for the tread width, they often mean the depth. If you are not sure which a number refers to, ask.

How Wide Should a Stair Tread Be?

Residential code sets a minimum stair width of 36 inches. Most treads are cut to the width of the staircase, so a stair that is 36 inches wide takes a 36 inch tread. Wider stairs are common in open-plan homes and run to 42 or 48 inches.

Treads are often sold in standard lengths and cut down to fit, so the stock length is usually the next size up from your stair. See stair riser height and tread depth for the code limits and for the wider set of stair dimensions.

How Deep Should a Stair Tread Be?

The residential minimum is 10 inches, measured nosing to nosing. Typical homes land between 10 and 11 inches. Deeper treads are easier and safer to use, which is why the 7-11 comfort rule pairs a roughly 7 inch riser with an 11 inch tread.

Depth is also where the nosing comes in. A retail tread is usually sold with the nosing already formed on the front edge, so its depth includes the overhang. The nosing projects between 3/4 and 1 1/4 inches under the residential code where the tread is shallower than 11 inches. See stair nosing: what it is and which type you need.

How Thick Are Stair Treads?

Solid wood treads are typically about 1 to 1 1/4 inches thick. Thickness is not about looks. It is what lets the tread span the gap between stringers without flexing, so it depends on how far apart the stringers are and what the tread is made of. The residential code does not set a tread thickness, so follow the tread maker's span guidance for your stringer spacing.

Two other thicknesses matter if you are changing flooring:

• A plank or tread cover laid over the existing tread adds its own thickness, commonly in the 4 to 8 millimeter range for rigid-core vinyl, which is roughly 0.15 to 0.3 inch, plus adhesive
• Thin carpet-grade treads under old carpet are often not built to be seen and may not be a good base for a new surface

That added thickness changes your riser heights, which is covered in the section on adding flooring in stair riser height and tread depth.

Do Stair Treads Come in Standard Sizes?

Yes, in the sense that treads are sold in common lengths and depths. No, in the sense that stairs themselves are not standard. Staircases vary from step to step, and walls are rarely square. That is why a template for each step is worth the time.

How to Measure Your Own Treads

• Width: measure the narrowest and widest point of each step, wall to wall, and use the larger figure for ordering stock and the smaller for the final fit
• Depth: measure from the face of the riser to the front of the nosing, and also note how far the nosing overhangs
• Thickness: measure at an exposed end or a cut edge if you can, not at a worn center
• Open ends: note any step that is open on one or both sides, because those need a finished return

Measure every step, not just one. Tread sizes drift by a fraction of an inch up a staircase, and the measurement guide walks through the stair-nose measurements in detail.

Treads, Risers, and Matching Your Floor

If you are covering the stairs rather than replacing them, the thing that matters most is how the front edge will be finished. A matching stair nose is what makes the tread read as part of the floor. See the guide to how to install LVP on stairs.

If your floor came from Home Depot, Lowe's, or Floor & Decor and you have five or more stairs, you can send the brand, color, and SKU through Find My Stair Match and StairMatch will review the match. You never need to send in flooring or samples.