Erläuterungen zu den Größen und Formen von Treppenstufen: Abmessungen, gesetzliche Mindestanforderungen und so bestellen Sie Sonderanfertigungen

Getting your stair tread dimensions wrong is one of the most common — and most expensive — mistakes in a staircase project. A tread that’s too shallow makes people feel unstable; one that’s too thick changes the riser height and throws off every other step in the run. Before you order, it helps to know exactly what each measurement means, what your local building code requires, and what shape your staircase actually needs.

This guide covers the three core measurements, code minimums for residential and commercial stairs, the ergonomic formula most designers use, common stair shapes, and how to measure before ordering.

The Three Core Stair Tread Dimensions

Every stair tread has three dimensions that matter for both safety and fit.

Depth (Run) Depth is the front-to-back distance your foot lands on — the horizontal surface you step onto. This is the most safety-critical measurement: too shallow and there isn’t enough surface for a full footstep, particularly going downstairs.

Dicke Thickness is how tall the tread board itself is. This affects the finished riser height of each step, so getting it wrong throws off the entire staircase geometry. It also determines how many times the tread can be sanded and refinished over its lifetime.

Length (Width) Length runs side to side across the staircase. On a standard enclosed staircase this equals the distance between walls; on an open-sided staircase it runs to the edge of the structure.

Code Minimums: Residential vs. Commercial

Building codes set the floor, not the ideal. Comfortable stairs are usually larger than the minimum.

Residential Stairs (IRC / IBC Standard)

Source: International Residential Code (IRC) R311.7. Local amendments may apply — always confirm with your architect or building inspector.

Commercial Stairs (OSHA / IBC Standard)

Source: OSHA 1910.25; IBC Section 1011. Commercial and industrial projects require a licensed engineer to confirm compliance.

The Ergonomic Formula

A widely used rule for comfortable stair proportions:

2 × riser height + tread depth ≈ 600–640 mm

This formula, sometimes called Blondel’s rule, reflects the natural stride length of a walking adult. A staircase that hits this range feels natural to climb without conscious effort.

Example that works:

• Riser = 170 mm
• Tread depth = 260 mm
• 2 × 170 + 260 = 600 mm ✓

Example that feels steep:

• Riser = 190 mm
• Tread depth = 240 mm
• 2 × 190 + 240 = 620 mm (within range but at the steeper end)

When designing a new staircase, choose a riser height first — one that divides your total floor-to-floor rise into a whole number of steps — then set the tread depth so the formula lands between 600 and 640 mm.

DuraMagicFloor Standard Production Ranges

The table below shows the dimensions we cut to as standard. Sizes outside these ranges are available on request with a custom quote.

In inches (approximate):

Our standard depth range of 280–300 mm sits comfortably above the IRC minimum of 254 mm, placing it in the comfortable-use zone for residential stairs. Our thickness range of 15–25 mm covers both retrofit applications (thinner boards where subtread height is already fixed) and new construction (thicker boards where the full tread height is part of the design).

Every tread is cut to your exact specification. There is no minimum order quantity.

Stair Shapes: Which One Does Your Staircase Need?

Straight Tread

The standard rectangular board used on a straight-run staircase. Length, depth, and thickness are all that need to be specified.

Curved Tread

Used on bowed or sweeping staircases where the front edge follows a radius. Because the curve must match the specific geometry of that staircase, curved treads are made to a radius specification from a stair plan rather than off a standard size chart.

Winder Tread

Found where a staircase turns a corner without a landing. Winder treads are wedge-shaped — narrower on one side, wider on the other — so each one is effectively a unique shape within the same staircase. These are made to a stair plan.

How to Measure Your Staircase Before Ordering

For replacement treads, measure each step individually rather than assuming they are all identical — particularly on older homes where settling has caused variation.

1. Depth — from the front edge of the tread to where it meets the riser behind it, not including the nosing overhang.
2. Dicke — measure the tread you are replacing directly, or measure the subtread height in new construction.
3. Länge — wall to wall on an enclosed staircase, or edge to edge on an open-sided staircase.
4. Note the shape — identify where the staircase is straight, where it sweeps, and where it winds around a corner, since each section needs a different tread shape.

If any steps vary in size — common on staircases older than 30 years — measure every step and flag the variation when you send your order.

Custom Sizes, No Minimum Order

The ranges above cover most residential and light commercial projects. DuraMagicFloor cuts every stair tread — straight, curved, or winder — to the exact length, depth, and thickness you specify. No minimum order quantity applies whether you need one staircase’s worth of treads or a full development project.

From the Factory

Our stair treads are produced at our facilities in Zhejiang, China and Thailand. Every batch is cut to customer specification on CNC equipment, which means the depth, thickness, and length you specify is what arrives — not a stock size trimmed to approximate fit. For projects where treads need to match an existing hardwood floor, we can cut from the same production batch as the flooring order to minimize color and grain variation between the floor and the stairs.

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