Replacing your kitchen sink can make your kitchen look new. To get the right new sink, you must measure your old one. This guide shows you how to measure your sink space step by step. Getting the right measurements is the first big step to a successful sink swap. It helps you pick a new sink that fits perfectly into your kitchen countertop and cabinet base. This saves you time, money, and headaches later.
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Gathering Your Measuring Tools
You do not need many tools to measure your sink. Just a few basic items will do the trick. Having the right tools makes the job much easier and helps you get correct numbers.
You will need:
- A metal tape measure: This is the best tool. It stays stiff when you pull it out, which helps measure long, straight lines.
- A pen or pencil: To write down your numbers.
- Paper or a notebook: To keep your measurements safe.
- A flashlight (optional): This helps you see in dim spaces, like under the sink cabinet.
- Gloves (optional): The area under the sink can be dusty or dirty.
Getting Ready to Measure
Before you start pulling out your tape measure, take a few quick steps. This gets the space ready and makes measuring easier and cleaner.
- Clear the area around the sink: Take away dishes, drying racks, and anything else on the counter right next to the sink.
- Clean the sink edges: Wipe down the top edge of the sink and the counter right next to it. Dirt can make your measurements off.
- Look underneath: Open the cabinet doors under the sink. See how the sink is held in place. Look at the pipes. This helps you understand the space you are working with.
- Turn off the water: It is a good idea to know where the water shut-off valves are. You will need them later when you replace the sink. You do not need to turn them off just to measure, but knowing where they are is smart.
Measuring Different Sink Types
Kitchen sinks come in different styles. How you measure depends on the kind of sink you have now. The two main types are drop-in and undermount. You might also have an apron-front sink.
Measuring a Drop-In Sink
A drop-in sink is also called a top-mount sink. It has a rim or lip that sits on top of the counter. This rim holds the sink in place. Measuring a drop-in sink is usually simpler than measuring an undermount sink.
Exterior Dimensions
First, measure the full size of the sink, including the rim.
- Measure the width: Place your tape measure on one side of the sink rim. Stretch it straight across to the other side. Measure from the very outer edge of the rim on one side to the very outer edge on the other side. Write this number down. This is the total width.
- Measure the length: Place your tape measure on the back rim (closest to the wall). Stretch it straight forward to the front rim (closest to you). Measure from the outer edge of the back rim to the outer edge of the front rim. Write this number down. This is the total length.
These numbers give you the maximum size of the sink that sits on the counter. This is part of the kitchen sink dimensions you will need.
Countertop Cutout
Next, you need to know the size of the hole in the counter that the sink drops into. This is called the countertop cutout dimensions. This is a very important measurement. The new sink must fit into this hole.
Measuring the cutout can be tricky because the sink rim covers the edge of the hole.
- Measure inside the rim: Place your tape measure under the rim. Go from the inside edge of the rim on one side to the inside edge on the other side. Do this for both the width and the length. This gives you a close idea of the cutout size.
- Look for clips: Drop-in sinks are held in place by clips underneath the counter. Sometimes, you can see the edge of the cutout next to these clips or near the sink edge from below. Use your flashlight to look up from inside the cabinet.
- Check the sink’s guide: If you know the make and model of your old sink, you might find its guide online. The guide often lists the needed cutout size. This is the most accurate way if you can find it.
Write down the estimated width and length of the countertop cutout. This measurement is key when you measure sink size for replacement. The new sink’s body must fit inside this hole, and its rim must be bigger than this hole.
Measuring an Undermount Sink
An undermount sink sits below the countertop. The edge of the counter is polished and hangs slightly over the sink edge. This type of sink gives a smooth look to the counter. Measuring an undermount sink is a bit different because there is no rim on top of the counter.
Exterior Dimensions
You need to measure the full size of the sink bowl itself. You will measure from the outside edges of the sink body.
- Look underneath: Go into the cabinet under the sink. Look up at the sink body.
- Measure the width: Measure from the outer edge of the sink bowl on one side to the outer edge on the other side. Measure the widest part if the sink is not a simple rectangle.
- Measure the length: Measure from the outer edge of the sink bowl closest to the back of the cabinet to the outer edge closest to the front.
- Measure the depth: This is also important for undermount sinks. Measure from the top edge of the sink bowl straight down to the bottom of the bowl. Do not measure from the counter, measure from the actual sink edge.
These are the exterior dimensions of your undermount sink.
Countertop Cutout
For an undermount sink, the countertop cutout dimensions are the finished edge of the hole in the counter. This is easier to measure than with a drop-in sink because the edge is visible.
- Measure the width of the opening: Place your tape measure on the polished edge of the counter cutout on one side. Measure straight across to the polished edge on the other side. Do this for the widest part of the opening.
- Measure the length of the opening: Place your tape measure on the polished edge of the counter cutout at the back. Measure straight forward to the polished edge at the front. Do this for the longest part of the opening.
These measurements give you the exact size of the hole in your countertop. When you measure undermount sink dimensions for replacing kitchen sink size, you need to match these cutout numbers closely. The new sink must have a rim or flange that is slightly larger than this opening so it can be attached securely from below. The sink body must fit inside the opening.
Measuring Other Sink Types
Some sinks have special designs.
- Apron-Front Sinks (Farmhouse Sinks): These have a large front panel that sticks out from the cabinet. You still need to measure the total width and length of the sink body. You also need to measure the height and width of the apron front itself. You will need to measure the cutout size in the counter behind the apron, and also check the opening size of the cabinet base below, as these sinks need a specific cabinet setup.
No matter the type, the key measurements are the total size of the sink and the size of the hole it fits into.
Measuring Critical Details
Beyond the main length, width, and depth, other smaller measurements are needed for replacing your kitchen sink size correctly.
Checking the Cabinet Base Size
The cabinet under your sink needs to be big enough to hold the sink bowl and the plumbing parts. This is the kitchen cabinet opening size.
- Measure the cabinet width: Open the cabinet doors fully. Measure the width of the open space from one side panel of the cabinet to the other. Measure at the top, just under the counter.
- Measure the cabinet depth: Measure from the front edge of the cabinet frame back towards the wall. Be careful of any pipes.
- Check for parts inside: Look for crossbars or supports inside the cabinet near the top. Some sinks need these removed or changed. Measure the clear space available.
Your new sink bowl must fit inside this cabinet space. Especially for large sinks or sinks with deep bowls, the cabinet size is very important. A sink that is too big for the cabinet will not fit, even if the countertop hole is correct.
Finding Countertop Cutout Dimensions
We talked about this for drop-in and undermount sinks. It is so important it is worth looking at again. This is the exact size of the hole cut into your counter for the sink.
For drop-in sinks, you are estimating this by measuring inside the lip or finding the old sink’s guide. For undermount sinks, you measure the visible opening edge.
Why is this so important?
- If the new sink body is bigger than the cutout, it will not drop in or fit up from below.
- If the new sink body is much smaller than the cutout, there might not be enough counter edge to support it (undermount) or the rim might not cover the gap (drop-in).
- You usually do not want to cut your countertop hole larger if you can avoid it. It is messy and costly. It is much easier to find a sink that fits the hole you have.
So, measure the width and length of the existing countertop cutout dimensions carefully.
Measuring the Drain Hole
You might need to know the size of the sink drain hole diameter. Most kitchen sinks have standard drain hole sizes.
- Standard drain size: The most common size for a kitchen sink drain is 3.5 inches (about 89 mm) in diameter. This is the size needed for most garbage disposals and sink strainers.
How to measure it:
- Look at the drain opening in the sink bowl.
- Measure straight across the widest part of the hole.
While most are standard, it is good to check, especially if you have an older sink or a very unusual one. Knowing this helps you choose the right drain parts or garbage disposal for your new sink.
Checking Faucet Holes
Your old sink probably has holes drilled in it or the counter for the faucet and other things like a soap dispenser or sprayer. When measuring for a new sink, you need to pay attention to these faucet holes. This is called measuring faucet holes.
- Count the holes: How many holes are there? One? Two? Three? Four? More? Count them carefully.
- One hole is usually for a single-handle faucet without a base plate.
- Two holes might be for a single handle faucet with a sprayer or a separate soap dispenser.
- Three holes are often for a faucet with separate hot and cold handles and perhaps a sprayer or soap dispenser.
- Four holes or more allow for extra items like air gaps (required in some areas) or water filters.
- Measure the spacing: If you have more than one hole, measure the distance between the centers of the holes. This is important for faucets that have a wide base or separate handles. Measure from the center of one hole to the center of the next. Standard spacing for three-hole faucets is 8 inches between the two outer holes (called 8-inch spread).
Your new sink needs to have the same number of holes in the same places as your old faucet setup, or you will need to buy a new faucet that matches the new sink’s holes. If you are getting a new counter, you can drill new holes anywhere, but if keeping the counter, the existing holes matter greatly.
Making Sense of Sink Dimensions
Now you have a list of numbers: sink exterior size, countertop cutout size, cabinet size, drain size, and faucet hole count/spacing. What do these numbers mean when you are shopping? This section helps you interpret kitchen sink dimensions and look at standard kitchen sink sizes.
Sink sizes are usually given as Length x Width. Sometimes Depth is included too (Length x Width x Depth).
- Length: The measurement from the back edge (near the wall) to the front edge (near you).
- Width: The measurement from the left edge to the right edge.
- Depth: The measurement from the top edge down to the bottom of the bowl.
Standard Sink Sizes
Kitchen sinks come in many sizes, but some are more common than others. These are standard kitchen sink sizes. Knowing these sizes helps you know if your sink is a standard size or something less common.
Many standard sizes are designed to fit into standard-sized kitchen cabinets. Base cabinets are often 24, 27, 30, 33, or 36 inches wide. Sink manufacturers make sinks to fit these cabinets.
Here are some common standard kitchen sink sizes (these are rough overall exterior sizes for drop-in sinks or common cutout sizes for undermounts, cabinet size needed is usually a few inches wider):
| Sink Type | Common Width Range | Common Length Range | Common Depth Range | Fits Cabinet Base (Approx.) |
|---|---|---|---|---|
| Single Bowl | 15 – 30 inches | 15 – 22 inches | 6 – 10 inches | 24 inches and up |
| Double Bowl | 22 – 48 inches | 18 – 24 inches | 6 – 10 inches | 30 inches and up (often 33, 36) |
| Low-Divide | 30 – 36 inches | 18 – 22 inches | 8 – 10 inches | 33, 36 inches |
| Apron Front | 20 – 40 inches | 18 – 24 inches | 8 – 10 inches | Special apron-front cabinet (size matches sink width) |
(Note: These are typical ranges. Many other sizes exist. Always check specific sink specs.)
These standard sizes are helpful starting points. If your measurements are close to these, you will have many options. If your sink is an unusual size, you might have fewer choices, or you might need to consider changing your counter or cabinet.
Common Dimensions Explained
When you look at sink specs online or in a store, you will see several sets of numbers.
- Overall Dimensions: This is the total outside size of the sink (like the measurements you took including the rim for a drop-in). This tells you how much space the sink takes up on the counter.
- Bowl Dimensions: This is the size of the inside of the sink bowls (Length x Width x Depth of the usable washing space). A sink might have large overall dimensions but small bowls, or smaller overall size with deep bowls.
- Cutout Dimensions: This is the size of the hole needed in the countertop. For drop-in sinks, the manufacturer gives a recommended cutout size, usually a bit smaller than the overall size. For undermount sinks, they give the maximum outer dimensions of the sink flange/body, and the cutout is typically made right along the outer edge of the sink bowl (or slightly inside or outside, depending on the desired look – called reveal).
When you measure sink size for replacement, comparing your countertop cutout measurement to the new sink’s required cutout dimension is the most important step for getting a proper fit in the hole. Then, check your cabinet opening size against the new sink’s overall dimensions to make sure the bowl will fit inside the cabinet box.
Putting Measurements to Work
You have your numbers. Now it is time to use them to find a new sink. This is about replacing kitchen sink size correctly.
Matching Your Measurements
Here is how to use your measurements when shopping:
- Start with the Countertop Cutout: This is usually the fixed part you cannot easily change. Look at sinks where the required cutout size is the same or very close to your existing cutout.
- For drop-in sinks: Your existing cutout must match the new sink’s listed cutout size.
- For undermount sinks: Your existing cutout is the visible hole. The new sink’s body must fit inside this hole, and its mounting flange must be wider than the hole. Match the overall dimensions of the new undermount sink to ensure its body fits the hole, and check the manufacturer’s instructions for the exact cutout needed for mounting.
- Check the Cabinet Base: Make sure the overall dimensions of the new sink (especially the bowl size and depth) will fit inside your kitchen cabinet opening size. There needs to be space for the sink and plumbing.
- Consider Sink Type: Are you sticking with drop-in or undermount? If you have laminate counters and a drop-in sink, switching to undermount is difficult or impossible without a new counter. If you have solid surface (granite, quartz, etc.) and an undermount, switching to drop-in is easy, but the hole might be bigger than standard drop-in cutouts, meaning the sink rim must be wide enough to cover it.
- Match Faucet Holes: Choose a new sink that has the same number of faucet holes in the right places as your current faucet, unless you plan to buy a new faucet too.
Using your measurements, you can narrow down your choices greatly. Many online sink stores and manufacturers list all these dimensions clearly.
When Sizes Don’t Match
What if you cannot find a sink that exactly matches your countertop cutout dimensions or cabinet opening size?
- Small Differences: A small difference (like 1/4 inch) in the countertop cutout might be okay, especially for drop-in sinks where the rim offers some cover. But check the new sink’s specs carefully. For undermounts, even small differences in cutout size can affect how the sink mounts.
- Larger Differences (Countertop):
- If the new sink needs a smaller cutout: This is hard to fix if you keep the same counter. You cannot easily make a hole smaller. You would likely need a new countertop.
- If the new sink needs a larger cutout: You can cut the counter hole bigger. This needs special tools and skill, especially for solid surface counters. It creates dust and mess. Many people prefer to avoid this and find a sink that fits the current hole.
- Larger Differences (Cabinet):
- If the new sink is too big for the cabinet: You might need to change the cabinet. Sometimes, removing a crossbar or trimming part of the cabinet side can work, but this depends on the cabinet structure. In some cases, a wider sink needs a wider base cabinet.
This is why measuring accurately first is so important. It tells you if replacing kitchen sink size is a simple swap or a bigger project involving the counter or cabinets.
Tips for Success
- Measure Twice: Always measure everything at least two times to be sure your numbers are right.
- Write Everything Down: Keep all your measurements in one place. Take photos of your setup (underneath, top view) to help you remember details.
- Round to the Nearest 1/8 or 1/4 inch: Extreme precision is not always needed, but be accurate to a level that helps you match sizes.
- Check Specific Sink Specs: Do not just rely on general “standard” sizes. Always look up the detailed dimension sheet for any sink you are thinking of buying. It will show overall size, bowl size, and required cutout size.
- Consider Bowl Configuration: While measuring size, think about what you want in a new sink. Do you want one big bowl, two equal bowls, or one large and one small bowl? This affects the overall sink width you will need.
- Think About Material: The material (stainless steel, composite, cast iron) does not change the measuring process, but it affects the sink’s weight and how it is installed.
Why Accurate Measurements Matter
Getting your kitchen sink dimensions right is the most important step when you measure sink size for replacement.
- Proper Fit: The new sink will drop in or mount correctly. No gaps around the edges. No forcing it into a space too small.
- Easier Installation: A sink that fits makes the installation process much smoother. The pipes will line up better, and the mounting hardware will work as designed.
- Avoid Costly Mistakes: Buying a sink that does not fit means you have to return it (if possible), pay for restocking fees, or even buy a new counter. Accurate measurements save you from these problems.
- Better Function: A sink that fits the cutout and the cabinet space properly will work better and last longer. It will be supported correctly.
Taking a little time to measure carefully now will pay off big time when you install your new sink. It ensures you get the right replacing kitchen sink size for your specific space.
Frequently Asked Questions (FAQ)
H5 What are standard kitchen sink sizes?
Standard sizes vary, but many drop-in sinks are designed to fit into standard cabinet widths like 24″, 30″, or 36″. Common exterior lengths are 20-22 inches, and widths range from 15 inches for a small single bowl to 48 inches for a large double bowl. Depths often range from 6 to 10 inches.
H5 How do I measure my sink size for replacement?
You need to measure the total outside length and width of your old sink. You also need to measure the size of the hole in your counter (the countertop cutout dimensions). For undermount sinks, also measure the depth. And check the space inside your cabinet base.
H5 Is it easier to replace a drop-in sink or an undermount sink?
Usually, replacing a drop-in sink with a new drop-in sink is the easiest. The new sink drops into the existing hole. Replacing an undermount with a new undermount is also fairly direct if the sizes match. Switching between types (drop-in to undermount or vice versa) is harder and might need changes to your countertop or cabinet.
H5 Can I put a bigger sink in my existing counter hole?
Generally, no. The hole in your counter (the cutout) is a fixed size. A new sink’s body must fit inside this hole, and its rim (for drop-in) or flange (for undermount) must be bigger than the hole to be supported. To put in a bigger sink, you usually need to make the counter hole bigger, which can be difficult and costly, or get a new countertop.
H5 How important is the kitchen cabinet opening size?
Very important. The sink bowl and plumbing must fit into the space inside the cabinet under the counter. A sink might fit the hole in the counter, but if the cabinet is too narrow or has supports in the way, the sink will not install properly.
H5 How do I find the countertop cutout dimensions for a drop-in sink?
Since the sink rim covers the edge, you can estimate by measuring inside the sink lip. The most accurate way is often to find the model number of your old sink and look up its specs online. The manufacturer’s guide will list the required cutout size for that specific sink.
H5 What is the standard sink drain hole diameter?
The standard size for a kitchen sink drain hole is 3.5 inches in diameter. This size works with most standard drain fittings and garbage disposals.
H5 Why do I need to count faucet holes?
The new sink must match the number and spacing of holes needed for your faucet setup. If you have a faucet that needs three holes, your new sink deck or countertop must have three holes in the right places. If the new sink has a different number of holes than your old faucet needs, you will have unused holes or need to buy a new faucet that matches the new sink.
H5 What measurements are needed to measure undermount sink for replacement?
You need the sink’s overall exterior length, width, and depth. More importantly, you need the size of the finished opening in the countertop above it (the countertop cutout dimensions). You also need to check the available space inside the cabinet base below.
H5 What if I want a different style sink, like an apron-front?
Apron-front sinks need special cabinets designed with an opening for the apron. You would need to measure the sink’s full dimensions, the specific apron dimensions, the countertop cutout behind the apron, and confirm you have (or will install) the correct type and size of cabinet base.
Taking the time to do these measurements right makes sure your new sink fits perfectly and looks great in your updated kitchen. Good luck!