How to Measure for Curtain Rods

Installing Curtain Rods

The trickiest part of hanging curtains is knowing where to put the curtain rod. It differs based on a few factors including the style of the window, the type of window covering, and the height of the ceiling.

Standard Curtain Rod Sizes

There are a few standard curtain rod size ranges you can choose from:

  • 28-48 inches in length
  • 48-84 inches in length
  • 66-120 inches in length
  • 120-170 inches in length

These options are available in most stores and will fit most standard-size windows. However, you shouldn’t settle for a standard rod size and “try to make it work” if it doesn’t quite match the dimensions of your window. Usually when people do this, the window treatment looks out of place and cheaply made.

Instead, we highly recommend taking custom measurements for your curtain rod and designing the rod accordingly. This way, you can ensure that the rod fits perfectly within or above the window frame to create the ideal design with your window treatment.


Step 2: Determine Curtain Rod Length

Curtain rod length is entirely up to you. However, we suggest following one of these two formulas to determine optimal curtain rod length:

  • Add 20% to your previously recorded measurements
  • Add six inches to both sides of the window frame or casing

By adding 20% or six inches on either side, you ensure that when your curtains are open (also known as “stack back”), they don’t engulf the entirety of your window. You should account for your stack back to cover about one-third of your window.

If you’re looking for a convenient, adjustable curtain rod that can be used interchangeably with different windows in your home, give Kwik-Hang’s curtain rods a try. They’re available in 24-48” widths and 48-86” widths, so there’s no need to rack your brain trying to find a specific rod.



How to Calculate the Right Measurements for Hanging Curtains

Before you start hanging curtains, make sure the panels are wide enough to cover your home's windows. You don't want to be rudely awakened by a beam of sunlight that the curtains don't block, so measure your window dimensions before purchasing or making your curtains. The total width of your curtain panels should add up to about two times the window's width.

Choosing the correct curtain length for your windows is also important. Besides looking awkward, too-small curtains visually shorten your space, making ceilings appear lower. Too-small curtains also make the room look smaller overall. Curtains that drag on the floor could pose a tripping hazard and collect dust more easily. For the ideal middle ground, curtains should hover just above the floor.

To find the right curtain length, measure from the floor to where you'll hang the rod (usually 4 to 6 inches above the window frame). Otherwise, hanging the curtain rod just below the ceiling is a simple design trick that makes your ceilings appear taller. Curtains come in standard lengths like 63, 84, and 96 inches. Choose one closest to your measurement, erring on the side of a few inches longer than shorter.

Additionally, be sure to choose a curtain rod that's wider than your window. This allows curtains to be pulled completely to the side of the window and makes the space feel larger. The rod itself should be 8 to 12 inches longer than the window's width, which allows for 4 to 6 inches on either side.

Related: 19 Impactful Ways to Dress Multiple Windows in a Row

low table and patterned curtains Credit: Nicholas Johnson

One or Two Rods?

Another point you need to take into consideration is whether you plan to use a single curtain rod that spans the entire window frame or two rods that rest on either side of the window. This choice will affect the size of the rod:

  • If you’re hanging one rod, use the above tips to measure how long it needs to be. Note that if you use a long, single rod that spans across multiple windows, you may need a center supportive bracket to ensure it doesn’t sag.
  • If you’re hanging two rods, ensure that they are of equal length. They should still span a few extra inches outside of the window frame and be centered over each corner of the window frame.

Things to Consider

Alpa Prod/Shutterstock

Alpa Prod/Shutterstock

When determining the curtain rod size you need for your window, consider some of these things for the best fit. 

  • Curtain material and stack on the sides when open
  • Ample space above and beyond the window for longer or shorter curtains
  • Weight of the curtain material 
  • Width of the rod
  • Sufficient supporting brackets 
  • Room for decorative finials on the ends

Curtain Material Stacking

It is ideal to have curtain rods extend four inches or more beyond the window frame. This space allows the curtains to stack on the sides when open and still provide light through the window. 

Shorter curtain rods will block the natural light with a stack that partially sits on the side of the window. Although it is completely fine to have some stacking on the window’s edge, you should not cover more than 3 inches of the window frame. 

Weight of Material For Rod Width

The curtain material can also be a determining factor to what size of rod you need to hang. Thicker fabrics will require wider rods to help support the weight. Consequently, some sheer fabrics don’t have larger rod pocket access and require a smaller diameter curtain rod. 

Traditionally, curtain rod sizes will range in diameter from one to three inches in width, depending on the material you use and the length of the rod. For example, longer curtain rods will be thicker in diameter to support more window treatments, while small windows are fine with a thinner rod. 

Adequate Brackets

One critical consideration for lengthy curtain rods is the supporting brackets. You want to ensure that you have enough brackets along the rod’s length to support the combined weight of the rod and the curtain material.

The longer your curtain rod, the more supporting brackets it requires for proper installation. A few rules of thumb include:

  • Small curtain rods of up to 30 inches don’t require a supporting bracket
  • Curtain rods up to 60 inches will need at least one supporting bracket
  • Extra-long rods up to 90 inches long will require at least two supporting brackets
  • Curtain rods up to 170 inches will need four or more supporting brackets

Additional End Space for Decorative Finials

Space surrounding your window frames may be an issue. For some homeowners, they opt for decorative finials on the ends of the curtain rods. These can range in size.

They also extend the length of the rod. If you are short on space, blunt caps can close off a curtain rod and not interfere with adjacent walls or other features in the room. 

Width Considerations

Use these tricks to make the drapes a standard width and to create the illusion of wider windows:

  • The standard distance from the window casing to the end of the curtain rod (excluding finials) on each side of the window should be four to 10 inches.
  • As a general rule, drapes will be open during the day, so make sure the curtain rod extends at least four inches on each side of the window’s inside frame.
  • To create the illusion of a wider window, extend the rod up to 10 inches beyond the window's frame.

Illustration: The Spruce / Emily Mendoza

Step 4: Find the Right Rod

Now, you’re ready to select your curtain rod!

Remember to account for curtain fabric and ideal lengths for different curtain fabrics and styles. For instance, some curtain fabrics look better floating above the floor, while other materials look better puddled on the floor.

Additionally, a thinner rod (5/8″ width) is best for sheer or lightweight curtains, while1-inch rods are suitable for heavier curtains and drapery.



Step 2: Mount curtain rod and hang curtains

After you've determined the proper placement, hanging curtains is easy. Use a screwdriver to install the curtain brackets; make sure the sides are even using a level. For particularly heavy curtains or rods, you might want to install wall anchors ($12, The Home Depot) to mount the brackets securely to the wall.

Place curtains on the rod. Thread the rod through the openings if your curtains have large grommets or eye holes. Otherwise, attach the panels to the rod with curtain rings or clips ($9, Target). Then set the rod into the brackets to hang the curtains.


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