How to Measure a Room for Flooring (Step-by-Step Guide)
A simple step-by-step guide on how to measure a room, stairs and awkward spaces for flooring.
After measuring thousands of homes across East Sussex for carpet, LVT and wood flooring installations, we’ve seen exactly where DIY measurements go wrong.
Before ordering new flooring, you need to know exactly how much space you need to cover. Measure incorrectly and you could end up ordering too little material – or paying for far more than you need.
This guide shows you how to measure any room quickly and accurately, even if it includes bay windows, L-shapes or chimney breasts.
Quick Formula for Measuring a Room for Flooring
A simple step-by-step guide to measuring rooms, stairs and awkward spaces
At Grimley Flooring, we measure hundreds of rooms every year across Eastbourne and Sussex as part of our flooring consultations, so we’ve seen exactly where homeowners often make mistakes.
Before ordering new flooring, the most important step is measuring your space correctly.
If the measurements are wrong, you could end up ordering too little flooring and delaying installation, or paying for far more material than you actually need.
The good news is that most rooms can be measured accurately with a tape measure, a quick sketch and a simple method.
This guide will show you how to measure:
✔ Simple rectangular rooms
✔ L-shaped rooms and awkward layouts
✔ Bay windows and curved areas
✔ Hallways, landings and staircases
✔ Chimney breasts and other obstacles
Most rooms can be measured in just a few minutes.
5 Steps to Measure a Room for Flooring
To measure a room for flooring:
- Measure the longest length of the room
- Measure the widest width
- Multiply length × width to find the area
- Break complex rooms into smaller rectangles
- Add all sections together
Example:
Room length = 5m
Room width = 4m
5 × 4 = 20m²
This gives you the net floor area used to estimate how much flooring you need.
Quick Room Measuring Checklist
Before ordering flooring, make sure you have recorded:
✔ Longest length of the room
✔ Widest width of the room
✔ Measurements for bays or additional sections
✔ Stair measurements if needed
✔ Chimney breasts or wardrobes
✔ Extra 10–15% allowance for fitting
Many customers find it helpful to screenshot this checklist before measuring.
Not confident measuring your rooms yourself?
Send us your room measurements and our team can check them and calculate exactly how much flooring you’ll need.
What You’ll Need
Most rooms can be measured using just a few simple tools.
• Tape measure (5m or longer)
• Pen or pencil
• Paper for a room sketch
• Calculator or phone
Avoid flexible fabric tape measures as they can stretch slightly and lead to inaccurate measurements.
Measuring Tip: Use Metres
Flooring is normally calculated in square metres (m²).
For this reason it is easier to measure rooms in metres rather than centimetres.
Example:
4 metres 25 cm = 4.25m
This makes calculations simple:
4.25 × 3.80 = 16.15m²
How to Measure Simple Rectangular Rooms
Most rooms fall into this category.
Living rooms, bedrooms and dining rooms are usually rectangular or square, which makes them very easy to measure.
Step 1: Measure the Length
Measure the longest wall from one side of the room to the other.
Write the measurement down.
Step 2: Measure the Width
Next measure the shorter wall of the room.
Record this measurement next to the length.
Step 3: Calculate the Area
Multiply the two measurements:
Length × Width = Area
Example:
5m × 4m = 20m²
Installer Tip
Always take 2 or 3 measurements to find the widest and longest points of the room.
Walls are rarely perfectly straight, so this helps avoid ordering too little flooring.
Quick Takeaway
Rectangular rooms are measured using length × width.
How to Measure L-Shaped Rooms and Irregular Spaces
Some rooms are not simple rectangles.
Examples include:
• L-shaped living rooms
• Open-plan areas
• Rooms with angled walls
• Zig-zag layouts
The easiest solution is to break the room into smaller rectangles.
Step 1: Draw a Simple Sketch
Sketch the room on paper.
It does not need to be perfect — you just need a place to record measurements.
Step 2: Divide the Room Into Sections
Split the space into rectangles you can measure easily.
For example:
An L-shaped room becomes two rectangles.
Step 3: Measure Each Section
Measure the length and width of each section.
Write the measurements on your sketch.
Step 4: Add the Areas Together
Example:
Section A = 12m²
Section B = 8m²
Total room size = 20m²
Quick Takeaway
Complex rooms can be measured by splitting them into rectangles.
Measuring Bay Windows
Bay windows can be measured as a separate section of the room.
Measure:
• Width of the bay
• Depth from the wall
Then add this area to the rest of the room.
Measuring Curved Bays
If the bay is curved:
Measure the widest point and maximum depth and treat it as a rectangle.
This slightly overestimates the area, which is usually helpful when ordering flooring.
How to Measure Hallways, Landings and Stairs
Hallways and staircases often include several connected sections.
The easiest approach is to measure each section separately.
Measuring Hallways
Measure hallways the same way as a room:
Length × Width
If the hallway turns a corner, simply split it into sections.
Measuring Landings
Landings are measured the same way as hallways.
However, measure over the stair nosing to the step below.
Record:
• Longest length
• Widest width
Measuring Different Types of Stairs
Staircases come in many shapes, including:
• Straight stairs
• Stairs with quarter or half landings
• Bullnose starting steps
• Winder or kite steps (triangular turning steps)
Although these designs look different, the basic measuring method is the same.
Each step is measured using two main dimensions:
Width – the distance across the staircase
Length (tread depth) – measured from the back of the step towards the stair nose
Even with winding or angled steps, installers normally measure the widest usable part of the tread.
Quarter and half landings can simply be measured like small rectangular rooms (just don’t forget to measure over the nose!).
Complex room layout?
L-shaped rooms, bay windows and staircases can make flooring calculations tricky.
Our team regularly helps customers measure unusual layouts and plan installations correctly.
Measuring Around Chimney Breasts and Obstacles
Many rooms include features such as:
• Chimney breasts
• Built-in wardrobes
• Alcoves
• Pipe boxing
• Structural columns
There are two easy ways to handle these.
Option 1: Ignore Small Obstacles
If the obstacle is small, it is often easiest to measure the room as a full rectangle.
The small amount of extra flooring rarely causes problems.
Option 2: Subtract the Obstacle
For larger obstacles, measure the room as a full rectangle and subtract the obstacle area.
Example:
Full room area = 20m²
Chimney breast = 1m²
Net flooring area = 19m²
Turning Your Measurements Into a Flooring Order
Once you know the net area, you can estimate how much flooring you need.
It is always wise to allow extra material for:
• Cutting and trimming
• Pattern matching
• Future repairs
Pattern Matching and Pattern Repeat
Some flooring designs include repeating patterns that must align during installation.
This is common with:
• Patterned carpets
• Some sheet vinyl designs
• Decorative tile layouts
What Is Pattern Repeat?
Pattern repeat refers to the distance between identical points in a design.
Example:
If a carpet pattern repeats every 60cm, extra material may be needed so the design lines up correctly.
Because of this, the amount of flooring required may be greater than the room size alone suggests.
Typical Allowance
Patterned flooring may require extra material depending on the design, this can range from 10% to over 75% additional material.
Your flooring retailer can normally calculate the exact amount.
Got your room measurements?
Send them to us and we can help you:
• Calculate the exact amount of flooring
• Allow for pattern repeat and wastage
• Choose the best flooring for your space
Ordering Carpet and Sheet Vinyl
Carpet usually comes in 4m or 5m wide rolls.
Add around 10cm to both length and width to allow for trimming during installation.
Ordering Luxury Vinyl, Laminate and Wood Flooring
For flooring sold in boxes:
• Start with the total area
• Add 10% for standard installations
• Add 15% for diagonal or herringbone layouts
Example:
Room area = 20m²
Box coverage = 2.2m²
20 ÷ 2.2 = 9.09
You will need 10 boxes of flooring.
Always round up to the next full box.
Ordering Underlay
Underlay is usually calculated using:
Net floor area + 5% extra
Example:
Room = 20m²
Add 5% = 21m² underlay
Need Help Measuring Your Space?
Measuring a room for flooring is usually much simpler than people expect. By recording the longest length and widest width, breaking complex layouts into sections, and allowing extra material for fitting, you can calculate a reliable estimate for almost any room.
If your space includes stairs, bay windows or unusual shapes, professional measuring can help ensure accuracy and avoid costly mistakes.
But by breaking the space into simple sections, you can usually get a reliable estimate in just a few minutes.
If you’d prefer complete accuracy, our team can measure your home using laser measuring equipment and professional planning software.
This helps minimise waste, ensures accurate ordering and makes installation smoother when your new flooring is fitted.
Got your room measurements?
Email them to us and we can help you:
- Calculate the exact amount of flooring
- Allow for pattern repeat and wastage
- Choose the best flooring for your space
“My wife and I are absolutely thrilled at Simon Grimley’s expertise in laying a stair and landing carpet which had a complex pattern requiring a substantial level of planning and detailed thought. His advice and options in the process were invaluable, and that together with his obvious skill in the actual laying of the carpet has produced a transformational outcome of complete pleasure.”
alex, eastbourne
Reviews from Sussex homeowners
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