Sizing a new kitchen sink is an important step before making this key purchase for your home renovation. Getting accurate measurements will ensure your shiny new sink fits perfectly into your existing countertop opening.
First, clear everything out from around and inside the sink. Have a tape measure, pencil, and paper ready to note down the dimensions. Determine if you currently have a drop-in or undermount kitchen sink since replacement sinks come in these two main types.
To measure properly, run the tape measure across the exact width and length of the sink’s outer edges. For depth, measure from the top of the sink rim straight down to the bottom. Check the depth in both the front and back since some sinks are deeper in the front section where the faucet fits. Record your sink’s overall dimensions and any special details that a new sink should match. With these key measurements, you’ll be ready to shop for the perfect sink size to flawlessly fit in your kitchen’s countertop cutout space.
Measure Kitchen Sink Depth
Clearing everything out from under the sink is the first step in maintaining good oral hygiene. Small gaps between partial denture teeth and your natural teeth provide the perfect niche for plaque to accumulate. To ensure a thorough cleaning, follow these steps:
Write down the sink depth dimension. Also measure sink length and width. For undermount sinks, measure from edge to edge on the counter cutout. For drop-in sinks, include overhang over the counter. Check that the depth works for your base cabinet size. Compare to potential replacement sink depths during selection. Carefully follow the manufacturer’s specifications for cutout and installation.
Gather Your Measuring Tools
Before starting, gather the following tools:
- Tape measure
- Ruler
- Pen & paper for notes
- Flashlight (to see rear corners)
Make sure you have a clear workspace to measure. Remove everything from inside and around the edges of the sink.
Determine Your Existing Sink Type
There are two main kitchen sink types:
Topmount (Drop-in)
These sinks drop into a countertop opening and their rim rests on top of the counter. They are the most common type installed in residential kitchens.
Undermount
Undermount sinks attach below the countertop, creating a seamless countertop-to-sink transition. They have a modern, sleek look.
Check under your countertop’s front edge to see if there is a sink rim or mounting brackets. This will confirm what style your current sink is.
Measure A Drop-In Kitchen Sink
Start by clearing everything out from under the sink. Use a tape measure to measure the length and width on the top outer edges of the existing sink. For length, measure from the left outer edge to the right. For width, measure from the back outer edge to the front. Also measure the depth by placing a straightedge ruler across the top of the sink and measuring from there to the bottom.
When selecting a new drop-in sink, allow for slight overhang. Measure the countertop opening length and width. Compare to potential replacement sink dimensions, allowing for maybe 1/4 to 1/2 inch larger sink size. Check that the sink depth fits the base cabinet, leaving room for plumbing. Confirm faucet holes line up. Carefully follow manufacturer instructions for cutout size and installation.
Key Sink Dimensions to Measure
These are the essential measurements needed:
Length
The sink length runs side-to-side across the sink bowl.
Width
The width spans the sink from front to back.
Depth
Depth is the measurement from the sink’s top edge vertically down to its bottom.
Corner Radii
Note whether your sink has rounded or square inside corners.
Measure Length & Width
For both length and width, take an interior measurement from inner sink edge to inner sink edge.
- Top mount sinks: Measure from the sink’s outer rim or lip
- Undermount sinks: Measure from the sink bowl’s top edges
Use a flashlight to see rear sink corners. Write down the length and width.
Measure Sink Depth
Depth is measured on both the left and right sides from the sink rim/top down to the bottom. Undermount sinks should be measured from the countertop surface down.
Note any slope or angle – Some sinks may be deeper in the front section. Capture any difference between the front and back depth.
Other Potential Measurements
- Drain placement – Measure from sink sides and back
- Number of holes needed for faucets/accessories
- Height of sink apron (front facing section)
Consider Your Countertop & Cabinet
Will you be installing your new sink in the existing countertop space? If so, confirm the cutout opening is large enough for your desired replacement sink.
Or will you have a new countertop installed to fit your sink? If so, provide the countertop fabricator your new sink dimensions.
For undermount sinks, measure the cabinet base interior to ensure adequate room for the sink size and mounting brackets.
Standard Kitchen Sink Cutout Size
The standard kitchen sink cutout size depends on the type and dimensions of the sink being installed. Common sizes include:
| Sink Type | Standard Cutout Size |
| Undermount sink | Equal to sink dimensions |
| Drop-in/Topmount sink | 1/4″ to 1/2″ larger than sink |
| Farmhouse sink | Following manufacturer specifications |
When replacing a sink, the cutout is typically made to match the original sink size. Allowance should be made for faucets, backsplashes, counter overhangs, and side appliances. Corner radii and sink lip size should also be checked to ensure proper coverage. Following manufacturer instructions for cutout and installation is always recommended.
Measurement Tips from Pros
- Use a sink template – Some sinks come with a cardboard template with exact dimensions. This can be handy for double checking your measurements.
- Snap photos – Take photos of the empty sink base from all angles to reference later.
- Mind the margins – Leave a 1/8″ – 1/4″ margin around the sink perimeter for any underside mounting hardware or sealant.
- Confirm access – Ensure adequate room for faucet hoses, shutoff valves, P-traps, garbage disposals, etc. within the cabinet.
Special Considerations
Farmhouse/Apron Sinks
Note overall length and apron height. The apron front will need to align with your cabinet face frame.
Corner Sinks
Pay attention to radius sizes, especially in a corner installation.
Double Bowl Sinks
Measure both bowls individually for length and width. Write down any divider size too.
How To Measure Kitchen Sink Undermount
To measure for an undermount kitchen sink, start by clearing the area under the existing sink. Remove everything from the base cabinet so you can access the walls and plumbing.
First, measure the existing sink hole width and length. Then measure from the top of the counter to the floor. This will give you the sink depth. Also measure the distance between the sink hole and the backsplash, as well as between the sink hole and any appliances, like the dishwasher. Compare your measurements against sink sizes to find one that will fit the existing hole. Allow room for any faucet, soap dispenser or spray hose. When installing, follow the manufacturer’s directions and seal the edges to prevent leaks.
Frequently Asked Question
What tools do I need to measure a kitchen sink?
You’ll need a tape measure, straightedge, and pen and paper to record the dimensions.
Should I measure the sink or the countertop opening?
Measure both the sink outer edges and the countertop cutout size to find a replacement sink that will fit.
How do I measure sink depth correctly?
Place a straightedge ruler across the top of the sink and measure from there straight down to the bottom.
What dimensions should I measure on the sink?
Measure the length, width, and depth of the sink bowl along with any additional relevant areas.
How accurate do my measurements need to be?
Take each measurement at least twice to ensure accuracy for finding the right replacement sink.
Conclusion
Accurately measuring your existing kitchen sink is crucial when replacing it or installing a new one. Take measurements of the sink outer edges – length, width and depth. For drop-in sinks, allow for overhang over the countertop cutout. Undermount sinks should match cutout dimensions.
Also measure from the sink hole to walls, backsplash, and appliances. Check faucet placement and holes line up. When installing, carefully follow manufacturer kitchen sink cutout specs for your sink type. Allow room for plumbing and accessories. Taking detailed measurements helps ensure proper fit and function.