How to Measure for New Stair Tread Covers UK — Complete Guide

Getting your measurements right before buying stair tread covers or stair nosing is absolutely essential. A stair tread cover that is too short, too wide or the wrong depth will look unprofessional, create trip hazards and potentially waste money on products that cannot be used.

This complete UK guide covers exactly how to measure for new stair tread covers — with step by step instructions for every measurement you need, common mistakes to avoid and tips for getting a perfect fit every time.

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What Are Stair Tread Covers?

Stair tread covers — also known as stair nosing strips, stair edge trims or stair tread caps — are profiles fitted to the front edge and surface of stair treads. They serve several important purposes:

• Protect the stair tread surface from wear, scuffing and damage
• Provide a clear, visible step edge to reduce the risk of slips
• Cover damaged or worn stair tread edges
• Give a clean, professional finish to any staircase renovation

Stair tread covers are available in a wide range of materials including aluminium, LVT, laminate and PVC — in self adhesive and screw fix options to suit every staircase type. 

What Measurements Do You Need for Stair Tread Covers?

Before purchasing stair tread covers or stair nosing, you need four key measurements:

1. Stair Width — the full width of the stair tread from wall to wall or wall to balustrade

2. Stair Tread Depth — the horizontal distance from the front edge of the step to the back wall or riser

3. Stair Riser Height — the vertical height of each step riser

4. Nosing Projection — how far the existing nosing or tread edge projects beyond the riser face

Each measurement is covered in detail below.

How to Measure Stair Width

Stair width is the most important measurement for choosing the right length stair nosing or tread cover.

Step by Step — Measuring Stair Width:

• Step 1 — Using a tape measure, measure the full width of the stair tread at the widest point — from wall to wall, or from wall to balustrade post if applicable.
• Step 2 — Note the measurement in millimetres for accuracy.
• Step 3 — If your staircase has a balustrade or newel post at one or both ends, measure to the inside face of the post — not the outside.
• Step 4 — Repeat for every step — stair widths can vary slightly, particularly on older properties. Always use the narrowest measurement to ensure your tread cover fits on every step.

Pro Tip: Always buy stair nosing slightly longer than your measured width — most profiles can be cut to exact length with a junior hacksaw for a perfect fit.

Standard UK Stair Widths:

• Standard residential: 860mm — 900mm
• Wider residential: 900mm — 1200mm
• Commercial: 1200mm and above

How to Measure Stair Tread Depth

Stair tread depth — also known as the going — is the horizontal distance you step on when walking up the stairs.

Step by Step — Measuring Tread Depth:

• Step 1 — Place your tape measure at the very front edge of the stair tread — the nosing point.
• Step 2 — Measure horizontally to the back of the tread where it meets the riser of the step above.
• Step 3 — Note the measurement in millimetres.

UK Building Regulations Requirements for Tread Depth:

• Domestic staircases: minimum 220mm going
• Other buildings: minimum 250mm going

If your tread depth is below these minimums, consult a building professional before proceeding with any staircase renovation.

How to Measure Stair Riser Height

The riser height is the vertical measurement of each step — from the top surface of one tread to the top surface of the next tread above.

Step by Step — Measuring Riser Height:

• Step 1 — Place your tape measure on the top surface of the lower tread.
• Step 2 — Measure vertically up to the top surface of the next tread above.
• Step 3 — Note the measurement in millimetres.
• Step 4 — Measure every riser on the staircase — riser heights should be consistent but can vary on older properties.

UK Building Regulations Requirements for Riser Height:

• Domestic staircases: maximum 220mm rise
• Other buildings: maximum 190mm rise

Pro Tip: Consistent riser heights are critical for safety — if risers vary significantly, this should be corrected before fitting new stair tread covers.

How to Measure Nosing Projection

The nosing projection is how far the front edge of the stair tread overhangs beyond the face of the riser below. This measurement is important for choosing the right stair nosing profile width.

Step by Step — Measuring Nosing Projection:

• Step 1 — Using a straight edge or ruler, hold it vertically against the face of the riser.
• Step 2 — Measure horizontally from the ruler to the front edge of the nosing.
• Step 3 — Note the measurement in millimetres.

UK Building Regulations Requirements for Nosing Projection:

• Maximum nosing projection: 25mm — 55mm recommended
• Minimum nosing return (underside): 15mm vertical

Pro Tip: A nosing projection that is too large — over 55mm — creates a trip hazard and may not comply with Approved Document K. If your existing nosing projection is excessive, a new stair tread cover can help bring it within compliance.

How to Choose the Right Size Stair Tread Cover

Once you have all four measurements, use this guide to choose the right stair tread cover:

Choosing the Right Width:

Always buy slightly longer than your measured width — cut to exact length for a perfect fit.

Choosing the Right Profile:

• Stair nosing only — protects the front edge of the tread
• Full tread cover — covers the entire tread surface and nosing
• Rubber insert nosing — provides additional slip resistance on the step edge
• LVT nosing — specifically for LVT flooring installations
• Laminate nosing — specifically for laminate flooring installations

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Measuring Tips for Different Staircase Types

Straight Staircases

Standard straight staircases are the simplest to measure. Measure width, depth and riser height on the first, middle and last step — use the smallest width measurement for ordering.

Winder Staircases

Winder staircases have triangular or trapezoidal steps that turn corners. Measure the widest and narrowest point of each winder step — order to the widest measurement and cut to fit each individual step.

Spiral Staircases

Spiral staircases require careful individual measurement of each step as widths vary significantly. Measure each tread individually and note all measurements before ordering.

Curved Staircases

For curved or irregular staircases, standard rigid stair nosing may not bend to follow the curve. Consider flexible stair nosing profiles which can be shaped to follow curved stair edges.

Common Measuring Mistakes to Avoid

1. Measuring only one step Always measure every step — stair widths and depths can vary, particularly on older properties. Use the smallest width measurement for ordering.

2. Forgetting to account for balustrade posts If your staircase has newel posts or balustrade at the ends, measure to the inside face of the post — not the outside. Your nosing must fit between the posts.

3. Not measuring nosing projection If your existing nosing projects too far, a new tread cover may change the step geometry. Always measure nosing projection before ordering.

4. Ordering exact length without cutting allowance Always order slightly longer than your measured width to allow for cutting to exact size. A nosing cut too short cannot be extended.

5. Measuring in centimetres instead of millimetres For accurate ordering, always measure in millimetres — stair nosing dimensions are specified in mm and small errors in centimetre measurements can result in ill-fitting products.

Frequently Asked Questions

How do I measure stair width for stair nosing?

Measure the full width of the stair tread from wall to wall or wall to balustrade post using a tape measure. Measure every step and use the smallest width measurement when ordering. Always order slightly longer than your measurement to allow for cutting to exact size.

What size stair nosing do I need?

For standard UK staircases up to 900mm wide, a 0.9m length stair nosing suits most applications. For wider stairs, choose 1.2m or 2.7m lengths. All stair nosing strips can be cut to exact length for a perfect fit.

How do I measure stair tread depth?

 Measure horizontally from the front edge of the stair tread to the back wall or riser face. UK Building Regulations require a minimum going of 220mm for domestic stairs.

What is nosing projection?

Nosing projection is how far the front edge of the stair tread overhangs beyond the face of the riser below. UK guidance recommends a nosing projection of 25mm — 55mm for most staircases.

Can stair nosing be cut to size?

Yes — all our stair nosing strips can be cut to any required length using a junior hacksaw or standard metal cutting tool. Always measure carefully before cutting.

How many stair nosing strips do I need?

Count the number of steps on your staircase — you need one stair nosing strip per step. For staircases with steps wider than 0.9m, choose longer lengths to avoid joins.

Ready to order your stair tread covers?

Browse our complete range of stair nosing strips — aluminium, LVT, laminate, vinyl, oak and rubber insert options available with fast UK delivery on all orders.

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For more expert guides on stair nosing, read our complete:

"How to Install Stair Nosing UK"

"Stair Nosing Buying Guide UK"

"UK Stair Nosing Regulations 2026"

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