​Interior DIY: How to measure carpet

Johannes van Graan Johannes van Graan
Carpet Tiles Industasia Walls & flooringCarpets & rugs
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Nothing beats a good ol’ hardwood floor, but sometimes one wants a softer underfoot sensation. And for those instances, we resort to lovely carpets for our homes.

But whether you are considering installing those carpets yourself or just want to have an idea of your carpet dimensions with you when you go carpet-shopping, some special considerations need to be taken into account when measuring for carpets.

To measure for wall-to-wall carpeting, you will need:  

• a measuring tape or a laser distance measurer 

• a calculator  

• some graph paper and a pencil, should you choose to draw your layout.

1. How to measure how much carpet I need

Measure width x length: Measure the maximum width and length at the room's widest points and multiply these measurements to give you an idea of the total square metres required (carpet prices are usually per square metre), e.g. 2m x 4m = 8m². 

To calculate an approximate price, take the carpet square metre price (e.g. £40.00) and multiply it by your total square metres (for instance, £40.00 x 8m² = £320.00). 

Measure any indentations: Not all rooms are perfectly square or rectangle, which means you will need to measure any indentations too, such as a fireplace, bay window etc. This is crucial to ensure that all of the carpet you buy can be utilised effectively, helping you minimise cost and waste.

Measure to the middle of doorways: A common mistake when it comes to measuring carpets is measuring simply from wall to wall. And unless your room is entered by a step, all rooms have a doorway leading into them. And some rooms have additional doorways to closets, bathrooms, etc. 

When measuring these rooms, you need to measure right into the middle of the doorway. This will add 5 to 7cm to your overall measurement; thus, if you have a doorway at either end of the room, you could be up to almost 15cm beyond the exact room dimension.

homify hint: What if your room includes recesses or chimney breasts? Then you must still measure the complete surface area as your new flooring will need to be cut around them. If this is not easy to calculate, work out individual areas and write these onto your diagram. You can always add them all together at the end to calculate the total area.

2. How do I measure for stairs?

Measure tread + riser: The tread is the part of the stairs that is stepped on. Starting with the top step, measure the depth of the tread. Be sure to extend the tape measure all the way to the outer edge of the step. The riser/fall of the step is the height between one step and the next (e.g. 20cm + 20cm = 40cm).

Add these two measurements together. Remember to add approximately 5cm per step to allow for covering edges or extra needed for underlay.

Count the number of steps: Multiply your first number by the number of steps you have to cover: e.g. 20cm + 20cm = 40cm x 12 steps = 4.8m. This will give you your length.  

Measure the width: Measure the width of the steps to know how wide the piece of carpet must be. Again add 5cm for allowances – this will be your width.

​3. What if the room is wider than a roll of carpet?

Amazing Design with Carpet Tiles Industasia Walls & flooringCarpets & rugs

Amazing Design with Carpet Tiles


There will always be a spacious room wider than a roll of carpet. For those cases, one will require a seam (or several seams) running along the edge of the room. For example, if your room is 5 x 6m, you will require extra carpet to fill in space beyond the width of the carpet.

Suppose you choose a carpet that comes on a 3m roll. For the above-sized room, you would require a 3 x 6m piece of carpet, and then you would have about 1 by 6m of room left to fill in.

The best way to handle this scenario would be to purchase another piece of carpet that is half the length of the room. Why half? Since you have about 1m of room left to fill in, and your carpet comes in a 3m width, you can cut the width in half (3 divided by 2), and use two pieces to fill in the remaining space. Better to be left with extra carpet than fall short, right? 

So, for this situation, you would buy an extra 3.5 by 3m piece of carpet, which would then be cut in half to give you two pieces 1.8 by 3m each (approximately). These can then be laid end-to-end to fill in the remaining space.

​4. Do I require a professional?

It is best to opt for a professional who does this sort of thing all the time. As you can see, calculating the requirements for carpet can be quite tricky.

If you have an unusual layout, are working with a pattern match, or are seeking to carpet several areas in your home, we recommend getting a pro in for the measuring and calculations. Professionals always know what to look for and will be there to point out something you may miss, advise on cost-cutting strategies, etc.

​5. What do I need to remember?

Amazing Design with Carpet Tiles Industasia Walls & flooringCarpets & rugs

Amazing Design with Carpet Tiles


Keep in mind that: 

• This is only an approximate guide. Your local carpet expert will usually want to be able to see the space and measure for themselves. This is advisable, as they can help to plan the most economical way to lay the carpet. 

• If you choose a patterned carpet design, you might need to order extra carpet to match this up across rooms or in unusual shapes. 

• Stairs with winders or half landings will require extra carpet for the changes in pile direction. 

• Underlay and fitting costs need to be added in as well. 

Since we’re talking about floors, we may as well go over The “always and never” guide to hardwood floor maintenance.

Did we help shine some light on the topic of measuring carpets?

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