How to Measure for Curtains

Written by: Jamie

Updated on: September 25, 2021

Learn how to fit your next curtains perfectly with our step by step curtain fitting tutorial.


Curtains can make all the difference to your home. They provide you with privacy, warmth, block beaming sunrays from waking you before your alarm – and play an important role in your home décor.

Getting new curtains is not a common task. People can go years without ever needing to buy new curtains. Therefore, when the time does come around, the most obvious question is how do you measure for curtains?

It’s a small task that shouldn’t be rushed, especially if you want to use your curtains to significantly enhance your home.


Choose a Mounting Technique

The first decision you need to make to ensure you measure for curtains accurately is how you will mount your curtains.

There are two different options, either outside mounted curtains or inside mounted curtains. Don’t worry – the curtains will always be inside your home. Here is what these two terms mean.

  • Outside mounted curtains: this is the most common type of mounting. When they are mounted outside, it refers to the outside of the window frame. The curtains in this instance will usually be attached to a rod above the curtain on the wall. This method makes the windows appear bigger and provides more blockage from outside light when closed as it goes further than the window’s edge. It also provides a more luxurious feel.
  • Inside mounted curtains: on the other hand, inside mounted curtains are attached to a rod that is inside the window frame. They are not as effective at blocking light or elegant, but they do offer the perfect aesthetic for those wanting to create a sleek and minimalist look.

Recommended Next: Don’t miss our guide to curtains and blinds that are perfect for reducing energy bills.

How to Measure Curtain Rods

The rod that your curtains will be attached to is another crucial decision. Most rods will extend up to six inches further than the edge of the window.

Yet, the position of the rod will have an impact on this decision. Here are your options:

1. Inside Trim

Those hanging curtains inside the window frame will have a shorter length at each side of the rod. Expandable rods are often a good option to ensure the perfect fit – and you should seek out rods with protective caps at each end.

2. Below Trim

Some window frames boast exceptional craftsmanship. If the top frame of your window is a feature piece you may want to leave this exposed and place the rod below the trim. These rods should aim to be between three and five inches longer at each side.

3. Above Trim

For those placing their rod above the window, they should do so between 6-12 inches above the frame. The higher you go the more elegant and sophisticated the windows will appear – and bigger! The same applies to the width. Six inches extra on each side is a good number to aim for.

Recommended: Do thermal curtains work effectively? Does the orientation of the window also affect energy efficiency? Read to learn more.

What Size Curtains Do I Need?

Next on the road to the right curtains is knowing what length curtains you need.

This is a step that comes before measuring so you can understand what type of aesthetic you want to create.

There are three main categories of curtain length and they are:

  • Above the windowsill – curtains can hang above the windowsill, but the margins are important. The curtain should not be more than a single cm higher than the sill or the curtains can appear too small for the window and not provide the privacy and warmth you were hoping for.
  • Below the windowsill – Most curtains hang below the windowsill at different lengths. For most people who want them to hang below but not all the way to the floor, the curtain should hang 15 centimeters beyond the sill.
  • Floor-length curtains – floor length curtains make a grand statement and make windows look bigger with maximum privacy. Although the name suggests they touch the floor, that is not something you want to happen as they can become dirtier more often and even worn or frayed at the edges. Instead, keep them around 1 cm from the floor.

Measuring the Length

Now that you have decided on a general style for your curtains, you need to actually measure the curtains for length. You may need a ladder and a second person to do this.

If you are placing your rod above the window, you do not need to measure this but add the measurement to the final measurement taken from the top of the window frame to the length desired (to either just above the sill, below the sill or 1cm from the floor).

For example, if you are placing the rod six inches above the frame, simply add this number to your measurement.

Measuring the Width

How to measure for curtains should also consider the width. In fact, this measurement can be the most problematic because it affects the fullness of the curtains.

A general rule of thumb is that the curtains should be 1.5-3 times wider than the width of your window. If your window is 150 centimeters then, the curtains need to be 225 centimeters to 450 centimeters wide.

The wider they are the more full the curtains will look when drawn apart, while less wide curtains will look more fitted and minimalist.

Important tip #1: Check to see if the product listing states the width of the curtains as individual panels or as a pair. If they come as an individual panel you will need to double this to get the actual width of the curtains together.

Important tip #2: if you are unsure of the appearance you want to create, use a blanket or bedsheet over the windows to estimate how full or minimal the curtains will look.

And that’s how to measure curtains with design in mind!

About the Author Jamie

I'm an English teacher and writer. I'm passionate about the environment and love the tiny house movement!

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