How to measure rough opening new dishwasherMeasure twice, cut once: it’s an old adage that carpenters and builders live by. The same can also be said when it comes to installing your new appliances, only with new appliances, it’s measure twice, install once. If you don’t measure, you could end up bringing home a huge, heavy new appliance that doesn’t fit in your kitchen.

Take dishwashers for example: if you have an existing dishwasher you might think it’s as easy as pulling it out, recycling it, and installing the new dishwasher of your choice. It can be, but it’s better to be safe than sorry.

It’s true, most dishwashers are the same size, and the standard size of a dishwasher is 24 inches wide by 35 inches high by 24 inches deep. But unless you measure your dishwasher’s existing space, also called a rough opening, you’ll have no idea whether or not your designated spot will fit that size.

Why would the size change from when you installed your older dishwasher to a new one? Maybe you’re changing your floor and you’d like to put new tile underneath your dishwasher. The height of the tile (usually one inch) will affect the height of your rough opening.

measure new dishwasherYou could also have completely renovated your kitchen and installed new cabinets. By measuring you’ll be sure that the contractor or cabinet installer created the right rough opening for a standard built-in dishwasher.

If you find your rough opening measures smaller than the standard size, you can still have a new dishwasher. You’ll just have to choose a smaller portable dishwasher and buffer the sides with trim to hide the excess space.

It’s easy to measure for a dishwasher. 

What tools do you need to measure a dishwasher?

  • A tape measure: It’s best to use a contractor’s tape measure that shows specific measurements like 1/8 or 5/8.
  • Something to record your measurements: Don’t leave it up to your memory. Write down each measurement, and to be safe, take a photo of the measurements with your phone and email that to yourself—and include a little drawing if you can so you don’t forget which number goes with which side of the appliance.

How to measure for a dishwasher

Step 1: To measure the height of your dishwasher opening, put the end of your tape measure on the floor in front of the opening for your dishwasher. Use the left edge of the dishwasher opening first.

Step 2: Pull your tape all the way up until you’ve reached the bottom of the counter that rests over your dishwasher. Write that measurement down exactly.

Step 3: Move to the right side of your dishwasher and do the same measurement. Write that measurement down exactly.

Step 4: To measure the width of your rough opening, move your tape measure to the top left corner of your rough opening. Extend the tape across the opening to the right side, resting on the top right corner. Write that measurement down exactly.

Step 5: Take your tape measure and move down to the bottom left corner of your rough opening. Extend your tape straight across the opening to the bottom right-hand side, just like you did for the top. Write that measurement down exactly.

By measuring the width at the top and bottom, you can be sure that there’s no change in the size of the space. 

Step 6: To measure the depth of your dishwasher opening you can do one of two things. If you currently don’t have a dishwasher in the space, take your tape measure and move it to the back wall of your rough opening on the right side. Holding it in place, extend the tape out along the cabinets all the way to the front of your cabinets. Write that measurement down to measure for your new dishwasher

To be sure the depth is the same on both sides, do the same on the left-hand side, extending your tape from the left side back wall all the way to the front of your cabinets. Write that measurement down exactly.

If you have a dishwasher installed right now, you can still take the depth measurement. Take your tape measure on top of your counter and place it on the back wall of your kitchen. Pull it along your countertop to the edge where your cabinets stop. Write that measurement down. Because cabinets are generally set a standard size of 24 inches, that’s the measurement of depth for your dishwasher too.


The depth, width, and height should be the same on both sides, but if it isn’t, take the smaller measurements with you when you’re shopping for a new dishwasher.

Measuring for a dishwasher is quick, simple, and it can save you a lot of hassle after you’ve picked one out. Make sure it fits before you bring it home and you’ll be happily washing dishes in no time.

For more resources on dishwashers, check out Best Buy Canada’s major appliance help hub.

Shelly Wutke
Editor TV & Home Theatre
I'm a Vancouver freelancer and tech enthusiast. When I'm not writing you'll find me on my farm with my alpacas, chickens, and honeybees. Visit my website Survivemag


  1. Stumbled across this article and I am glad I did. I am about to purchase an 18’’ portable dishwasher and measuring the cabinet area is something I need to do. Thought it was going to be a quick 1-2-3, but I learned a few things that I didn’t take into consideration (like the depth of the washer. Video was also a huge help. Thanks for posting.

  2. Great article, thanks. One thing though:
    “The depth, width, and height should be the same on both sides, but if it isn’t, take the larger measurements with you when you’re shopping for a new dishwasher.”
    Wouldn’t I want the smaller measurements? Ie. if the width across the top is 23″ and across the bottom is 24″, a 23.5″ wide appliance will not fit.

    • You’re right, that’s a typo. You would definitely want the smaller measurements. Thanks for pointing that out!

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