How to measure a kitchen sink?

1 Before You Begin

An undermount sink, a drop-in sink and a farmhouse sink.

When learning how to measure a kitchen sink for replacement, first you need to know what type of sink you currently have. There are three main types of sinks: undermount sinks, drop-in sinks and farmhouse sinks.

  • Undermount sinks are installed below the countertop. The countertop covers the rim of this sink, so no part of the sink rests on top of the counter. 
  • Drop-in sinks are also called top-mount or self-rimming sinks. These sinks have a rim that rests on top of the counter’s surface. 
  • Farmhouse sinks or apron sinks have an exposed front and a deep basin. The basin is not covered by cabinets. 

Once you know your type of sink, prepare to take kitchen sink measurements by following these steps:

  • Empty out your kitchen base cabinet so that you have a clean area to work with when you measure that space.  
  • Make sure your sink is clear of dishes and clean.  
  • Take all measurements twice, just to ensure your measurements are accurate.  
  • Install will vary depending on sink type and measurement directions may be slightly different. 

2 Measure Your Kitchen Sink

A diagram illustrates how to measure your sink's width and depth.

When learning how to measure kitchen sink size, you may need to make some adjustments for your type of sink. Below we cover standard kitchen sink measurements, plus tips for how to measure undermount kitchen sinks and farmhouse kitchen sinks.

  • Using your measuring tape or a ruler, begin with the lip, or edge, that sits on the kitchen countertop. If you have an undermount sink, measure from the edge of the counter opening. 
  • Measure the length of your sink by placing the edge of your tape measure on the left edge of the sink and stretching it across to the right edge. Write down the length.   
  • Measure the sink width by placing your tape measure at the back edge of the sink (closest to the kitchen faucet) and stretching it across the sink basin to the front edge. Write down the width. 
  • Lastly, measure the basin depth. Place your straightedge ruler or your level across the top of your sink. Use your tape measure to measure the deepest part of your sink basin to the bottom edge of the ruler. Write down the depth.  
  • If you have an undermount sink, be sure to measure the height from sink to countertop. 
  • If you have a farmhouse sink, also measure the depth from the top edge to the bottom edge of the exposed front, in case these depth measurements differ.  

3 Measure Your Cabinet

 A man uses measuring tape to measure the width and depth of his sink base cabinet.

Now that you have your kitchen sink measurements, measure your cabinet space. When replacing a sink, it’s important that your new kitchen sink be the same bowl size (sink width and sink depth) of your current sink. Otherwise, you may have to replace your cabinet too. The sink cabinet measurements are going to determine exactly what size sink you can install.

  • Start by measuring the depth of your cabinet. Place your tape measure along the bottom of the cabinet and measure from the back to the front edge. 
  • Next, measure the total width. Place your tape measure along the bottom of the cabinet to measure from the left edge to the right edge.  
  • Now that you have a total number, subtract approximately 4-inches from the overall width and 1-inch from the depth to get your sink width.  
  • If you have a drop-in sink, be sure to measure the interior width of the sink top at the widest spot and then subtract the same 4-inches.  
  • If you are replacing a farmhouse sink, measure the height of the exposed front of your old sink. This will be the maximum depth of your new sink. 
  • If you are installing a farmhouse sink for the first time, you will have to remove the false cabinet drawers for installation. Measure from the top of the counter to the top edge of the cabinet door. Subtract at least 1-inch from this measurement for buffer space. This will be the maximum depth of your new sink. 

Tip: The most common size for standard sink base cabinets is typically 24-inches from back to front. 

4 Remove the Old Sink and Measure the Cutout

A diagram illustrates how to measure your sink cutout after you have removed the old sink.

You will need to remove your old sink to take this set of measurements. When doing so, be sure to shut off water valves that lead to the sink, disconnect the water lines and remove the faucet. Then disconnect the drain attachments and remove the sink.

  • With your old sink removed, measure the area just as you did in step 1.  
  • First, measure from side to side and then back to front. This is the total width available for your new sink.  
  • It’s important to pay attention to your corner ratio. Be sure the corner radius and the lip of your new kitchen sink are not smaller so that all gaps are covered. 
  • For an undermount sink, the cutout should match the new sink’s interior measurements. 
  • For a drop-in sink, keep in mind how much overlap you will need between the lip and the counter. 

Use all three methods to measure your sink to ensure you have the most accurate measurements. Now that you know how to measure a kitchen sink, you can find a new sink that’s a perfect fit.

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