What size of sink do I need for my kitchen layout?
What size sink do I need for my kitchen unit? A complete guide to measurements, standards and practical decisions
The seemingly simple question – how big a sink – breaks down into several interrelated dimensions, standards and compromises when examined more closely. A proven answer from practice is never just one number. It depends on the width of the unit cabinet, the thickness and material of the worktop, the type of installation, the number of basins in the sink, the presence of a drainer and, not least, how the family cooks and what they want to wash in the sink. This article will guide you through the entire decision-making process step by step – with specific numbers from real projects.
Basic dimension dictionary: what exactly to measure and where
Before choosing a sink, it is essential to understand that a sink has several dimensions, and not all of them refer to the same place. Retailers and manufacturers quote the so-called overall sink dimensions (outer frame), which are compared to the opening in the worktop. There is also the basin dimension (internal, usable space), which determines whether a large pot or tray from the oven will fit into the sink.
- Overall sink width – the distance between the outer edges of the frame from left to right. This dimension determines the minimum width of the unit cabinet.
- Overall sink depth – the distance from the front to the back edge of the frame. It must not exceed the working depth of the kitchen unit (usually 600 mm).
- Opening dimension – the dimension of the opening that is milled or cut into the worktop. It is always smaller than the overall sink dimension, as the edge (so-called flange or strip) must sit on the worktop.
- Internal basin dimension – the clear opening of the basin, measured at its upper part. In deep sinks, manufacturers also quote it at the lower part, where it is smaller due to rounded corners.
- Basin depth – the vertical distance from the top edge of the basin to the bottom. Commonly 160–230 mm, up to 250 mm in premium sinks.
These three levels of dimensions must be remembered, because when ordering a sink, it can happen that the customer reads only one dimension and during installation finds out that either the cut-out is too small or the sink hangs in the air without support. From practice, I know that the most common confusion arises here: a sink 780 × 500 mm does not mean that the cut-out will also be 780 × 500 mm – the cut-out is usually 15 to 25 mm smaller on each side.
Standard width of the kitchen cabinet: what does it all depend on
Kitchen units are delivered in modular widths in Central European practice: 400, 450, 500, 600, 800, 900 and 1000 mm. The sink is installed in the so-called sink cabinet, which most often has a width of 600 mm, but for simple sinks 500 mm is sufficient and for larger double-basin sinks with a drainer 800 or 900 mm is needed.
The depth of the worktop is 600 mm in the European standard (including the front strip of about 40–50 mm, so the usable depth is 550–560 mm). Therefore, the maximum overall depth of the sink must not exceed about 500–510 mm, so that there is space in the back for connecting the drain, trap and hot and cold water supply without the cables and hoses hanging out of the cabinet doors.
Typical combinations of cabinet-sink from practice
| Cabinet width | Recommended sink | Type of kitchen |
|---|---|---|
| 500 mm | single-basin, max. 480 × 440 mm | studio apartment, small kitchen, second sink |
| 600 mm | single-basin with a ledge, approx. 560–580 × 480–500 mm | standard kitchen, 2–4-room apartment |
| 800 mm | 1.5-basin or double-basin, 740–760 × 480–500 mm | family house, active kitchen |
| 900 mm | double-basin with a drainer, 860–880 × 480–500 mm | large family, serious home cook |
| 1000 mm | large double-basin or farmhouse sink | open space with an island, restaurant |
These numbers are approximate. The rule always applies: overall sink dimension = cabinet width minus 20 to 40 mm (space for mounting brackets and possible material expansion). The exact recommended cut-out dimensions can be found in the technical documentation of each sink.
Single-basin, double-basin or 1.5-basin: what will your kitchen choose?
The number and shape of the basins in the sink directly affect the dimensional requirements. It is not just an aesthetic decision – it has a functional and practical impact on daily cooking.
Single-basin sink
One spacious basin is king where large quantities are cooked – large pots, trays from the oven, roasts. A typical dimension of a single-basin sink is 500 × 440 mm to 600 × 500 mm in overall dimension (the internal basin is usually about 440–540 × 380–440 mm). Ideal for a 600 mm cabinet. Since the entire width is one basin, you have exceptional flexibility when washing large items.
Practical example: a customer with a small kitchen in a panel apartment (2.4 m long, 600 mm wide sink cabinet) originally wanted a double-basin sink, but after measuring we found out that she would end up with two basins with a width of only 180 mm – each would fit at most a glass. We chose a single-basin granite sink with an internal dimension of 490 × 400 mm and the problem disappeared.
Double Bowl Sink
Two basins of the same size – or one larger and one smaller – work well where one part is used for washing and the other for draining, or one is filled with water for soaking and the other has running fresh water. The overall size of a double bowl sink ranges from 760 × 440 mm in a compact version up to 1000 × 500 mm in premium models. You will need a minimum cabinet width of 800 mm, in practice rather 900 mm, if you want to integrate the draining board into the overall width.
1.5 Bowl Sink Format
A very practical compromise: one full basin (e.g. 340 × 400 mm inside) and next to it a smaller cut-out (e.g. 170 × 300 mm inside). The small cut-out is used for placing freshly washed items, for a colander or for soaking. The overall size is usually 740–800 × 440–500 mm, so it fits into an 800 mm cabinet. For medium-sized kitchens, this is the most universal choice.
How to correctly measure the sink cabinet and worktop
Before any purchase, perform these measurements. You will need a measuring tape, a pencil, and ideally someone to help with measurements in hard-to-reach areas.
Step 1 – width of the sink cabinet opening
Measure the internal width of the cabinet between the side walls (not including decorative strips). Subtract at least 20 mm on each side – this gives you the maximum overall width of the sink. To be sure, subtract 30 mm on each side.
Step 2 – depth of the worktop
Measure the actual depth of the worktop from the front edge to the wall (or to the rear connecting strip). If the worktop is covered by tiling at the wall, include the thickness of the tiling. The maximum overall depth of the sink must not exceed the depth of the worktop minus approx. 40–50 mm (space for the trap and plumbing at the back).
Step 3 – thickness of the worktop
A standard laminated worktop has a thickness of 28–38 mm. A stone (marble, granite, concrete) worktop can be 20 mm to 60 mm thick. The thickness of the worktop affects the height of the mounting brackets that come with the sink – with very thick worktops, standard brackets may be too short and must be replaced with alternative ones or the sink can be glued with silicone.
Step 4 – position of the drain pipe
Determine where the drain pipe exits the floor or wall. The distance from the side wall of the cabinet and the height of the outlet determine which side of the sink the basin drain must be placed (left or right drain), and what kind of trap will be needed. If you plan to install an automatic dishwasher, allow for the fact that a supply hose from the dishwasher will also enter the sink cabinet.
Size of the cut-out in the worktop: who determines it and how to make it
The manufacturer of each sink specifies the exact recommended size of the cut-out in the documentation. This size is smaller than the overall size of the sink, because the rim (flange) of the sink must protrude over the edge of the cut-out and rest on the surface of the worktop. Typically, the cut-out is smaller by 30–50 mm in width and 30–50 mm in depth compared to the overall size of the sink – depending on the width of the flange of the specific model.
Example: a granite sink with an overall size of 780 × 500 mm may have a recommended cut-out of 740 × 460 mm, i.e. the flange is 20 mm on each side. Some premium sinks with a thin flange profile have a cut-out only 10 mm smaller on each side – therefore always read the documentation of the specific model and do not rely on estimates.
The cut-out is most often made by a carpenter or kitchen installer using a router with a guide. The radius of the cut-out corners (rounded corners) must match the radius of the sink – most granite sinks have corners with a radius of R = 30–60 mm. If the radius of the cut-out is larger than the radius of the sink, the sink will not fill the gap in the corners and water will leak under the rim.
A detailed step-by-step procedure for the cut-out and installation of the sink can be found in the article Mounting a sink into a kitchen worktop: step-by-step guide, where the entire process is described including sealing with silicone and tightening the brackets.
Specific case: undermount versus topmount installation
In the Slovak and Czech practice, topmount installation still dominates – the sink lies on the worktop, the flange covers the edge of the cutout from above. In this installation, the overall size of the sink is larger than the cutout, which provides some tolerance when cutting.
Increasing popularity is gained by undermount (undermount) installation, where the sink is glued to the underside of the worktop (only for stone, glass or concrete worktops). In this case, the cutout is the same as or slightly smaller than the outer edge of the sink, because the sink is not visible from above and the entire surface of the worktop is flat. Precision of the cutout is critical here – a deviation of 2–3 mm is visible and cannot be corrected without replacing the worktop. The manufacturer specifies a specific cutout size for undermount installation and the corner radii must match.
Depth of the basin: why it matters more than you think
The depth of the sink is not only an ergonomic matter – it is also a technical parameter. Common basin depths are:
- 150–170 mm: shallow sinks, typical for compact solutions and bathroom sinks. In kitchen use, they are less practical – water splashes, a large pot does not fit.
- 180–200 mm: standard in the kitchen. Sufficient for the average family cooking needs.
- 210–230 mm: deep sink, comfortable for larger cooking. Most premium granite sinks fall into this size range.
- 250 mm and more: farmhouse or professional sinks. They require a lower cabinet or an individual solution for the height of the worktop.
Attention: the depth of the basin affects the free space under the sink. If the cabinet height is 720 mm (a common standard without a base), and we subtract 35 mm for the worktop and 200 mm for the basin, only 485 mm remains under the bottom of the basin – which is enough, but with deep basins of 250 mm and a low-mounted cabinet, it can happen that the trap collides with the bottom of the cabinet or the drain pipe has to go under 90 degrees, which worsens the flow.
Granite sinks and their dimensional specifics
Granite (quartz composite) sinks differ from stainless steel ones not only in material, but also in dimensional tolerances and weight. A granite sink with dimensions 780 × 500 mm can weigh 12–18 kg, which places demands on installation – the clamps must be tightly tightened and with larger sinks, temporary support is needed during the sealing compound drying.
Concrete example: granite sink Sinks BEST 780 Granblack is a model with an overall width of 780 mm, suitable for 800 mm wide cabinets. It is a double-basin sink with one main basin and one smaller drainboard, making it a very practical solution for family kitchens where cooking is done daily. The black color Granblack is very popular among granite sinks, but it requires a special approach to maintenance – more about it can be found in the article Maintenance of a granite sink: cleaning, removing limescale and stains.
For smaller kitchens or as an additional sink, the granite sink Sinks SOLO 560 Milk is interesting – a single-basin model with an overall width of 560 mm, suitable for a 600 mm wide cabinet. The color Milk (cream white) makes it suitable for light, modern kitchens. A single-basin compact model is ideal where space does not allow a larger sink, but you still want a comfortable interior space of the basin.
Drainboard: part of the sink or a separate accessory?
A drainboard (drainboard) is either integrated directly into the sink casting or comes as a separate accessory that is placed next to the sink on the worktop. The choice has a direct impact on the required overall size.
An integrated drainboard increases the overall size of the sink by 200–350 mm. If you have a 600 mm sink cabinet and want an integrated drainboard, you need to either extend the sink cabinet to 800 mm or reduce the basin itself.
The advantage of a separate drainboard is flexibility – you can remove it when you don't need it, use it on the other side of the sink, or choose a different shape. For example, Sinks drainboard VARIO COMPLET black is a modular system that can be configured according to your needs – the colander slides into the drainboard and can be moved to the left or right side. This is a practical solution where the drain pipe is on one specific side and you need the drainboard on the other, without the need to change the entire cabinet layout.
If you are considering black accessories, read the article Black sinks and accessories: what to know before buying about color surface durability?, where it is explained in detail why the black surface of different manufacturers can differ in resistance to UV radiation and chemical cleaning agents.
A colander also belongs to the sink. For example, Sinks colander black 450 × 200 × 102 mm is a solution for a large basin, where you need efficient draining of dishes – its dimensions 450 × 200 mm cover a large part of the basin floor and the depth of 102 mm ensures that the colander does not stand directly on the floor, so water freely drains. More about choosing a colander can be found in the article How to choose the right colander and drainboard for your sink?.
A practical helper in the cabinet next to the sink: Sinks shelf black 265 × 57(103) × 65 mm is hung on the inner wall of the sink cabinet and is used for storing small items – sponges, detergents, cords. Its dimensions of 265 mm in width and 65 mm in height make it suitable for places where space is limited, for example next to the trap and inlet valve.
Non-standard situations: corner sink, island sink, farmhouse sink
Corner sink
A corner sink is a specialty for kitchens where the layout forms an L-shape and a "dead space" remains in the corner. Corner sinks have an irregular shape – usually a square of about 800 × 800 mm with the basin placed diagonally. Dimensional measurement is more complex here, as both branches of the layout must be considered and the cutout must be symmetrical in relation to the corner. Corner sinks are rare and their production is more expensive, but in the right kitchen, they are exceptionally ergonomic.
Sink on an island
A sink on a kitchen island is visible from all sides. The limitation of wall depth is eliminated, but the width of the island becomes a constraint. A typical island depth is 900–1200 mm, so the sink can be deeper than in a wall-mounted layout. At the same time, water drainage must be considered – the connection to the sewer system runs through the floor, which requires planning already during the rough construction phase.
Farmhouse (Apron Front / Butler) sink
Farmhouse sinks (deep basin, exposed front panel of the sink facing the user) have completely different dimensional requirements. The front panel of the sink replaces the front panel of the cabinet, so the sink cabinet must be specially modified. These are usually custom modular solutions. The internal depth of the basin of a farmhouse sink typically reaches 200–300 mm.
Practical tips from installation practice
From real customer projects, the following errors and lessons repeatedly emerge:
- You did not measure with the tiles/backsplash: if there is a backsplash on the wall behind the sink and the countertop fits against it, the backsplash reduces the effective depth of the work surface. This must be taken into account when selecting the sink depth.
- You did not check the position of the plumbing connections: the hot and cold water supply valves must be inside the sink cabinet, not behind the sink. If the connections are too far forward or backward, the trap will not fit.
- You bought a larger sink than the cabinet: if the overall size of the sink is the same as the internal width of the cabinet, the sink will not fit – it must be mounted on brackets and the flange must protrude. Always leave a 20–30 mm margin.
- You did not verify the type of mounting: some sinks are intended exclusively for top-mount installation, others only for undermount. Attempting to install a top-mount sink as an undermount usually ends in a leak or a cracked flange.
- You overlooked the position of the drain hole: most sinks have a pre-drilled hole for the faucet (1–3 holes), some are without a hole and must be drilled on site. Drilling into a granite sink requires a special drill – using a standard bit risks cracking the sink.
If you are considering buying a sink together with a faucet as a set, read the article SET sink + faucet: is it worth buying together or separately?, where the advantages and disadvantages of combined purchases are discussed.
Material selection and its impact on dimensions and weight
The material of the sink indirectly also influences dimensional decisions. Stainless steel sinks are light (4–8 kg) and thin-walled, so brackets can support even larger dimensions without problems. Granite composite sinks are heavy (12–20 kg) and require solid mounting for large dimensions – sometimes they are even supported by consoles attached to the cabinet body. Ceramic sinks are the heaviest (20–40 kg) and require significantly reinforced cabinets.
Further material comparisons can be found in the articles How to choose a sink for your kitchen: granite, stainless steel or composite? and Granite vs. stainless steel sink: a comparison of durability, maintenance and price.
Frequently asked questions (FAQ)
What size sink is suitable for a standard 600 mm cabinet?
For a cabinet with an internal width of 600 mm, we recommend a single-basin sink with an overall size of maximum 560–575 mm in width and 480–495 mm in depth. The cutout in the countertop will be approximately 520–535 × 440–455 mm. A typical example is a sink of format 560 × 480 mm or 500 × 440 mm, where there is sufficient margin for brackets and sealing.
Can I install a smaller sink in a larger cabinet?
Yes, but the flange of the sink must rest on the work surface, not in the air. If the sink is significantly smaller than the cabinet, the sides of the cutout will end on the countertop and the work surface will be visible between the edge of the sink and the cabinet. This is not a functional problem, but may not look good aesthetically. The solution is to choose a sink so that the flange visually covers the cutout with an appropriate margin, at least 10–15 mm on each side.
What to do if the cutout in my countertop is larger than planned?
If the cutout in the old countertop is larger than the recommended cutout for the new sink, there are two solutions: either choose a sink with a wider flange profile (wider rim), which will cover the cutout, or use an additional cover profile (decorative strip). In the case of a significant difference (more than 30 mm), it is better to replace the countertop or use an insert. Always consult with an installer before purchasing the sink.
What is the minimum internal depth of the basin for comfortable washing?
From an ergonomic point of view, the minimum is about 170–180 mm, ideally 200–220 mm. Below 170 mm, water from a running faucet splashes out of the basin and a large pot cannot be cleaned with a built-in strainer. For families where cooking is active, we always recommend at least 190 mm, and 200–220 mm is standard for premium granite sinks.
How to determine whether my sink is for left or right drainage?
The drain of the basin can be symmetrical (center of the basin) or asymmetrical (left/right corner). The manufacturer specifies the position of the drain in the technical documentation or on the product image. The position of the drain must match the position of the drain pipe in your cabinet. With a symmetrical drain, you have more flexibility – the trap can be rotated as needed. More about drainage problems is covered in the article Common sink problems: clogged drain, cracked shell, trap leakage.
Can a granite sink be shortened or modified on site?
A granite composite sink cannot be shortened or sanded on site with standard tools – the material is very hard and will crack if you attempt to modify it. The only way is to choose the correct size from the beginning. A stainless steel sink can theoretically be shortened, but this will leave an irreversible deformation of the frame. Always measure twice, order once.
Conclusion: steps for selecting the correct sink size
The correct sink size is not chosen based on what you like in a picture – it is chosen through careful on-site measurements and a clear understanding of the relationships between the cabinet width, the overall sink size, the cutout size, and the internal basin space. If you are unsure, check the technical documentation of the selected model before ordering, compare the cutout size with what you can create in your countertop, and verify that there is enough space under the sink for the trap and plumbing.
The entire category sinks and sink accessories contains models in a wide range of sizes, from compact single-basin sinks suitable for small kitchens to large granite double-basin sinks for spacious kitchen islands. Technical specifications for individual products with precise cutout dimensions are also available – it is worth studying them before purchasing, not during installation.
Do you have a question about this topic?
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