When measuring for a new kitchen sink, you must find the exact size of your current sink opening or the countertop space available. This ensures the new sink fits perfectly without needing major countertop changes.
Replacing an old kitchen sink often seems hard. But, knowing how to measure correctly makes the job simple. This guide will walk you through every step. We focus on clarity so you get the right kitchen sink dimensions every time. We aim for easy reading. Think of this as a friendly chat about your DIY project.
Why Accurate Sink Measurement Matters
Getting the size wrong causes big headaches. A sink that is too big won’t fit. A sink that is too small leaves an ugly gap. This gap can trap dirt. It might let water seep under the rim. Measuring right saves time, money, and stress. It is the first, most vital step in measuring for a new kitchen sink.
Tools You Need Before You Start
Gather these simple tools first. They help you get precise numbers.
- Tape measure (a flexible one works best)
- Pencil or marker
- A straight edge, like a ruler or level
- Paper to write down your numbers
- Safety gloves (especially when dealing with old sinks)
Step 1: Deciding What Kind of Sink You Have
Kitchen sinks mainly come in two styles. Each style needs different measuring steps.
Drop-In Sinks (Top-Mount)
These sinks sit on top of the counter. The rim rests on the countertop surface. They are common and easy to replace.
Undermount Sinks
These sinks mount below the counter. The countertop edge is exposed. This style looks sleek but requires more precise cutting for the hole.
Step 2: Measuring for a Replacement Sink (Fitting a Replacement Kitchen Sink)
If you are fitting a replacement kitchen sink of the same type, the goal is to match the existing opening.
Measuring a Drop-In Sink Replacement
This is usually the easiest task. You measure the hole in your countertop.
Measuring the Opening Width
- Place your tape measure across the opening.
- Measure from the left edge of the hole to the right edge.
- Write this down. This is the drop-in sink cutout size for width.
Measuring the Opening Length (Front to Back)
- Measure from the front edge of the hole to the back edge.
- Write this down. This is the length measurement.
Important Note on Clearance
When replacing a drop-in sink, your new sink’s outer rim must be bigger than the hole you just measured. If the new sink rim is too small, it will fall through! Aim for a new sink rim that overlaps the existing cutout by at least 1 inch on all sides.
Measuring an Undermount Sink Replacement
Undermount sink measurement is crucial because the countertop edge must support the sink rim perfectly.
Measuring the Existing Sink Bowl
If the old sink is still in place, measure the bowl itself first.
- Measure the inside width of the bowl.
- Measure the inside length of the bowl.
- Measure the depth of kitchen sink bowl from the bottom up to the lip that touches the counter.
Measuring the Countertop Cutout (If the Sink is Still Mounted)
This is tricky. You need the opening size under the counter.
- Carefully look underneath the counter where the sink attaches.
- Measure the width of the hole cut in the stone or laminate.
- Measure the length of the hole.
Pro Tip: For undermount sinks, the size of the cabinet base below also matters. Check the inside width of your sink base cabinet. The new sink bowl must fit inside this space.
Step 3: Measuring for a Brand New Installation (New Countertop)
If you have new counters being installed, you are in charge of the final hole size. You need to know the standard kitchen sink sizes available, but your cabinet size dictates the maximum.
A. Checking Cabinet Size First
The cabinet that holds your sink is the biggest constraint.
- Open the cabinet doors below the sink area.
- Measure the width of the cabinet box from the inside wall to the inside wall.
- Subtract 3 inches from this total width (1.5 inches on each side for sink clips and mounting hardware). This is your absolute maximum sink width.
Example: If your cabinet is 36 inches wide inside, the largest sink you can install is about 33 inches wide.
B. Determining Desired Sink Bowl Size
Now, decide how big you want the basin to be. Do you wash large pots? You might want a deep, single bowl. Do you need a double bowl for washing and rinsing?
The measuring kitchen sink basin area is personal preference, but keep cabinet size in mind.
Single Bowl Sinks: Common widths range from 30 to 36 inches.
Double Bowl Sinks: Common widths range from 33 to 48 inches.
C. Choosing Between Drop-In and Undermount for New Counters
When dealing with new counters, you can choose your sink type.
Drop-In Sink Hole Size
For a drop-in sink, the drop-in sink cutout size must be smaller than the sink’s outer rim. Manufacturers often provide a template for kitchen sink installation or a precise cutout diagram.
- General Rule: The cutout size is usually about 1 inch smaller in both length and width than the overall sink dimensions. Always use the template provided by the sink maker!
Undermount Sink Mounting Area
For an undermount sink, the cutout in the countertop will be larger than the sink basin, but smaller than the sink’s mounting lip.
- Crucial Point: The rim of the undermount sink must have enough flat space to attach securely to the underside of the counter material (granite, quartz, etc.). This flat mounting area is usually 1 to 1.5 inches wide.
Table of Common Sink Sizes (Approximate)
Kitchen sinks vary greatly. Here are some common standard kitchen sink sizes in inches (Width x Length). These are for the sink basin itself, not the required countertop hole.
| Sink Type | Smallest Common Size (in.) | Average Size (in.) | Largest Common Size (in.) |
|---|---|---|---|
| Single Bowl Drop-In | 20 x 16 | 30 x 20 | 33 x 22 |
| Double Bowl Drop-In | 30 x 18 | 33 x 21 | 42 x 21 |
| Single Bowl Undermount | 18 x 14 | 25 x 16 | 32 x 18 |
| Farmhouse/Apron Front | 30 x 20 | 36 x 21 | 42 x 24 |
Step 4: Measuring Sink Depth
The depth of kitchen sink bowls is important for function and plumbing.
- Measure from the top rim (or the surface where the rim rests) down to the bottom of the basin.
- Shallow sinks are often 5 to 7 inches deep. These are good for shallow cabinets or if you have plumbing issues below.
- Standard sinks are 8 to 9 inches deep.
- Deep sinks are 10 inches or more. These hold large items but require deeper cabinets.
Plumbing Check: If you have a garbage disposal or double plumbing drains, make sure the new, deeper sink won’t make the pipes bump into the cabinet floor or the drain line coming from the wall.
Step 5: Measuring Faucet Holes and Accessories
Modern sinks often come with pre-drilled holes. If you are installing a new sink, you need to know how many holes you require for your chosen faucet setup.
Faucet Hole Layout
Look at the sink deck (the flat area behind the basin).
- One hole: For a single-handle faucet.
- Three holes: For a main spout, a hot handle, and a cold handle (older style).
- Four or Five holes: Often used for a main faucet plus a soap dispenser, spray nozzle, or air gap (for dishwashers).
If your current sink has four holes but your new faucet only needs one, don’t worry. Most sinks come with knockout plugs for unused holes, or you can buy decorative caps to cover them.
Measuring Faucet Placement
If you are fitting a replacement kitchen sink where the faucet is already mounted on the counter (not the sink itself), measure the distance between the existing holes.
- Measure the center-to-center distance between the main faucet hole and any side holes (like the soap dispenser).
- This ensures the new sink deck matches the existing faucet placement on the counter.
Finalizing Your Measurements: Creating a Template
When measuring for a new kitchen sink, especially if you are going from drop-in to undermount, or changing bowl configurations significantly, creating a paper template is the safest method.
Making a Template for Sink Installation
- Get the Sink: If possible, get the actual sink box before cutting the counter.
- Use the Manufacturer’s Template: Most high-quality sinks come with a cardboard template for kitchen sink installation. Trace this template directly onto the countertop material.
- If No Template Exists (For Replacement):
- Place a large sheet of paper (like kraft paper or cardboard) over the existing sink opening.
- Trace the exact outline of the hole onto the paper.
- If you are tracing the sink rim itself (for a drop-in), mark the outer edge.
- If you are tracing the required cutout for an undermount sink, trace the inside edge of the mounting lip.
- Transfer Measurements: Take this paper template to the store or show it to your installer. It visually confirms all the dimensions (length, width, faucet placement).
How to Measure the Sink Hole Measurement Precisely
The sink hole measurement is the most vital number when replacing a drop-in sink.
- Use your tape measure to find the smallest dimension across the opening (the narrowest width).
- Then, find the smallest dimension from front to back.
- These two numbers define the hole size. Always measure in multiple spots across the hole, as old cuts might not be perfectly straight. Use the smallest measurement you find for the width and length.
Special Considerations for Different Countertops
The material of your countertop changes how you measure and cut.
Laminate Countertops
Laminate is forgiving. If you are replacing an old drop-in with a slightly smaller one, the existing hole might be too big. You might need a special sink rim adapter or “apron” piece to cover the gap. If the new sink is slightly smaller, it is an easy fix.
Granite, Quartz, and Solid Surface Countertops
These materials require extreme precision. If you are cutting a new hole or enlarging an existing one:
- Undermount: The cutout must be perfectly smooth and sized exactly for the sink’s rim.
- Drop-in: The cutout must be slightly smaller than the sink rim so it rests securely.
- Professional Help: For stone, it is almost always best to have a professional fabricator handle the cutting based on the manufacturer’s template. Mistakes in stone are costly to fix.
Measuring for Large Sinks (Apron Front/Farmhouse)
Farmhouse sinks are larger and heavier. Measuring for a kitchen sink of this type involves the cabinet structure itself, not just the counter.
- Measure Cabinet Width: Measure the cabinet face opening exactly. The apron front must fit neatly against the cabinet doors or panels.
- Check for Support: Farmhouse sinks are very heavy when filled with water. Ensure your base cabinet structure can support the weight. Some require extra bracing inside the cabinet.
- Apron Height: If replacing an existing apron sink, measure the height of the visible front panel. The new sink apron must match this height so it sits flush with the surrounding cabinets.
Final Checks Before Purchasing
Before you buy your new sink, lay out your measurements one last time. Use this checklist:
| Check Item | Measurement Taken | Result (Yes/No) |
|---|---|---|
| Cabinet Interior Width (Max Sink Width) | ||
| Existing Cutout Width (If replacing) | ||
| Existing Cutout Length (If replacing) | ||
| Desired Sink Width | ||
| Desired Sink Length | ||
| Faucet Hole Count Needed | ||
| Sink Depth (Does it clear plumbing?) | ||
| Undermount Clearance (Is there 1.5″ rim space?) |
If you answered “Yes” to all checks related to the intended sink type, you are ready to shop. Accurate kitchen sink dimensions are now in your hands.
Frequently Asked Questions (FAQ)
What is the standard depth of a kitchen sink?
The standard depth of kitchen sink bowls is usually between 8 and 10 inches. Sinks shallower than 7 inches are considered shallow, and sinks deeper than 10 inches are considered deep-basin models.
Can I use a drop-in sink template for an undermount sink?
No. A drop-in sink template shows the hole needed for the sink to drop into. An undermount sink requires a different cut. The cutout must be sized to allow the sink’s mounting lip to glue securely to the underside of the counter. Always use the correct template for your sink type.
How do I figure out the correct drop-in sink cutout size?
For a replacement, measure the existing hole size. For a new installation, take the overall kitchen sink dimensions and subtract about 1 inch from both the length and width. Always defer to the template provided by the sink manufacturer for the most precise cut.
Do I need to measure the basin or the whole sink?
When buying a sink, you need the overall exterior dimensions (the rim size) to ensure it covers your hole (for drop-in) or fits your cabinet (for undermount). You also need the interior basin measurements for washing space and the depth for plumbing clearance.
What if my new sink is wider than my old one?
If you are fitting a replacement kitchen sink that is slightly wider than the old one, you might only be able to use an undermount style, as the new rim will cover the old hole. If it is a drop-in, and the new rim is larger than the old cutout, you will likely need a professional to cut the countertop larger.
What is the process for measuring kitchen sink basin separation for a double sink?
If you are replacing a double sink, measure the center divider between the two bowls. Ensure this divider width matches the new sink, or that the new sink configuration fits within the existing cabinet space.