Having a reliable step-by-step guide that has been tested and proven to work is crucial if you want to measure stairs for carpet installation with confidence. Even straight stairs are relatively hard to measure properly. If you have winding stairs, or curved stairs, accurate measurements start looking like one of the hardest things to achieve. However, if you remember to take detailed notes, a few measurements, and always keep the carpet pile in mind, you should be in a position to calculate the total amount of carpet needed to cover your stairs without a hitch. Having your staircase well-measured is the first step to getting a stair carpet that is durable and safe. It’s definitely a step in the right direction – pun intended. So, let’s see how to get it done.



The Short Version
Knowing all steps you need to take in advance would be beneficial to the successful completion of the process. So, just start with it:
- Step one should always be to measure the width of the stairs
- Write down the riser height and the stair tread. Use the same units of measurement throughout to avoid confusion
- Don’t forget to include the hallway and landing
- Note any half landings and details of a curved staircase
- Take measurements of all the stairs separately, including the top stair
- Draw a floor plan and organize your detailed notes to make the calculations
- Extra carpet and drop backs of at least 10% should be included in the final calculation

Things to Consider First
The various carpet materials call for different techniques for measuring. What is more, carpet pile should always be in the same direction. This is vital not only for your carpets to look better, but also for fitting. So, pay close attention to the pile direction when preparing the floor plan. While measuring a landing and stairs is more complex than measuring a normal room, careful attention to detail will ensure accurate results.
The underfloor heating and the carpet underlay also play a crucial role. They are important for heat distribution, but any professional carpet fitter will tell you they also affect the amount of carpet you need. Having or not underfloor heating also may affect the type of carpet material you are going to need.
Carpet Measuring Step #1
Take measurement of the stair width with tape measure. Use the widest point of the stairs. Look for overhangs and narrow edges and take them into consideration. Repeat for all stairs separately and double-check to ensure no mistakes were made in the process.
In case you measure for stair runners, you should measure the width even more carefully. Take detailed notes of the widest edge of every individual stair – particularly in case you are working on winding stairs and curved stairs. Accurate measurements are crucial for carpet stairs to ensure a perfect fit and professional finish.
Carpet Measuring Step #2
The horizontal part of your stair tread and the riser height, which is the vertical part, are the next focal points of the measure. Position the tape measure on the edge of the step and slowly extend it until it meets the vertical part. If you are working on curved stairs or winding stairs, you need to have each step measured individually.
Carpet Measuring Step #3
Don’t forget the landing and hallway. These are the top and bottom parts of the stairs. You need to measure the landing and hallway, because you will be installing carpets on them as well. Half landings should be included into your account as well. Make sure to take precise measurements especially in case of a curved staircase. These tend to affect the flow of the carpet pile significantly with this type of stairs. Also, you should consider the next tread while calculating, which means you should note each inner corner and narrow edge there.
Carpet Measuring Step #4
When measuring straight stairs, you can expect all measurements to be uniform. In the case of winding stairs and curved stairs, though, it’s normal for every step to have different dimensions. That is why it is very important to rather carefully measure the whole stair separately. Double check to make sure you have all the different measures accurately recorded.
Carpet Measuring Step #5
Look in the drop backs that you will need to include to make your measurements fitting correctly. No matter how close an attention you pay to the process, make room for mistakes. To do that, simply add a little extra carpet – around ten percent – to the final calculation. In such a way, you will avoid unpleasant surprises when the time for fitting the carpet comes.
Measuring Stairs with Turns or Curves
Measuring stairs with turns or curves is extra tricky. When dealing with curved or spiral stairs, you need to take individual measurements for each step as the dimensions can vary so much. Start by measuring the width of the stair at its widest point – remember that. Only then should you measure the length of the stair from the back of the tread to the front of the riser. Be sure to make a note of the direction of the curve and where the landings or turns are.
For the so-called L-shaped stairs, measure the length of the stair from the top of the landing to the bottom including the turn. For fancy spiral staircases, measure from the top of the landing to the bottom, make sure you account for the curve. Taking multiple measurements will help you get it spot on for your carpet.
Measuring Landings and Obstructions
When measuring landings and obstructions you need to account for any irregularities or obstacles that will affect the fit of the carpet. Measure the width and length of the landing including all and any alcoves or small spaces. Make a note of where any doors, windows or obstructions are that will surely impact the carpet installation. This will help you get a smooth and professional look.
Measuring Doors and Alcoves
When measuring doors and alcoves you need to consider both the width and depth. Measure the width from the wall to the edge of the door or alcove, and the depth from the wall to the very back. Make a note of any hinges, handles or obstructions that will affect the carpet installation. This will give you a pretty precise fit and finish.
How to Calculate the Total Carpet Needed
Now you have all your measurements, you can calculate the total carpet needed. Simply multiply the stair tread and riser height by the number of stairs. Add the landing and hallway area, half landings and the extra carpet. Now you know how much carpet you need.
Choosing the Right Carpet
Choosing the right carpet for your stairs and landing is crucial for ensuring durability and longevity. Consider the amount of traffic and wear the carpet will endure, as well as its style and design. High-traffic areas, such as stairs and landings, require a carpet that is both durable and resistant to wear.
Traffic and Wear
When choosing a carpet for your stairs and landing think about the traffic and wear it will get. Go for a high pile density and durable material like nylon or polyester. Also choose a carpet that matches your home’s style and is easy to clean. Look for stain resistance and low maintenance designs so your carpet stays beautiful and functional for years to come.
By following these tips and considering your stairs and landing’s specificities you’ll choose the right carpet for your home and have a beautiful installation.
Prepare the Tools Before you Start
The measuring process requires some special, yet simple tools to be taken care of correctly. So, before you proceed with the steps of taking carpet measurements, make sure that you have:
- A rule and/or a straight edge
- Tape Measure
- Carpet padding when required
- Calculator to calculate the total amount of carpet needed – the one on your smartphone will work
- Graph paper to rough sketch your floor plan
- Notepad and pen for detailed notes while you are doing the measuring

With these tools of trade at hand, you should be able to successfully finish the carpet measuring without an issue.
The Floor Plan Should Not be Ignored
In theory, you can calculate all your measurements without drawing a floor plan. However, taking the time to prepare one will make sure you don’t miss a landing measure, a detailed note you’ve taken or even an entire half landing. It’s easy to forget even a quite important detail without a floor plan, so just avoid confusion by sparing the time to draw one.
Final Thoughts
Installing carpet on stairs require quite accurate measurements. That is, if you are into safety, as well as seamless fits. Understanding how to measure stairs for carpet can take a little time, but it is well-worth the effort in the end. So, ensure your proper carpet installation today by taking the most accurate measurements of your curved stairs, straight stairs, or winding stairs today.