What size of sink do I need – how to measure the worktop before purchase
Why the sink size is not just a number on the box
When a customer comes into the store and says "I need a 60 cm sink," they usually have something different in mind than what the manufacturer lists in the catalog. And it is precisely this difference between what the customer thinks and what the manufacturer measures that causes most of the problems during installation. Suddenly it turns out that the sink is two centimeters longer than the opening in the countertop, or the opposite – the sink slides down because it is too small and has nothing to rest on.
This guide explains how to correctly measure the countertop, what the individual dimensions in the Alveus product names mean, and why it is always worth measuring twice before placing an order. If you are more interested in choosing a sink based on material or shape, also see other articles in our Knowledge Center – for example How to choose the right Alveus kitchen sink – material, shape and size or Single or double sink – which is suitable for your kitchen.
Three dimensions you need to know
Every sink has three basic dimensions: the outer dimension, the cut-out dimension (opening), and the depth. Each of these dimensions serves a different purpose and cannot be interchanged.
Outer dimension of the sink
This is the total width and length of the sink including the edge (lip) that rests on the countertop. In Alveus sinks, this dimension is usually 20 to 40 mm larger on each side than the cut-out itself. The outer dimension determines how much space the sink physically takes up on the countertop and whether it will even fit into the cabinet opening if you install the sink from below (i.e., from the bottom).
Cut-out dimension (cut-out opening)
This is the opening that you must cut or drill into the countertop. It is smaller than the outer dimension of the sink because the edges of the sink must be able to sit on the countertop. The manufacturer usually recommends that the cut-out be 2 mm smaller on each side than the outer dimension of the sink – so for a sink with a 20 mm edge, the cut-out will be 2 mm smaller on each side than the sink itself.
Sink depth (basin height)
The third dimension is the depth of the basin – how deep the sink is from the edge to the bottom. This dimension is important for two reasons: first, it determines how much space under the countertop the trap and drain need; second, it affects the comfort of use – a shallow sink fills up more quickly and water splashes, while a deep sink is harder to clean under a low countertop.
What do the numbers in the Alveus sink name mean?
Alveus labels its sinks with a numerical code that is based on the outer dimensions of the sink. For example, in the sink SET ALVEUS INTERMEZZO 130/81, the first number 130 means the width of the sink in centimeters and the second number 81 means the depth (in terms of front-to-back dimension, i.e., how far the sink extends from the edge of the countertop backward). This is therefore a double sink combination with an outer dimension of 1300 × 810 mm.
A similar labeling applies to the sink SET ALVEUS INTERMEZZO 30/91 – here the width is 300 mm and the front-to-back dimension is 910 mm, which corresponds to a small single sink variant suitable for narrower countertops or corner solutions.
The same logic applies to sinks made of black granite – for example, ATROX 50 black 91 + pop up trap has an outer dimension of 790 × 500 × 200 mm, where the number in the name (50) roughly refers to the width of the basin in cm, and 91 indicates the color variant. The actual dimensions are always listed in the product sheet.
Practical rule: always open the product sheet and look for three numbers – width × length × depth in mm. Never rely only on the trade name.
How to measure the countertop – step by step
Before you start measuring, prepare a steel tape measure (not a tailor's tape), a pencil, and paper. A mobile phone for taking photos is also useful – take photos of the existing cut-out and the direction of the drain pipe.
Step 1 – Measure the cabinet (lower part of the kitchen unit)
The internal width of the cabinet (between the sides from the inside) determines the maximum outer dimension of the sink. The sink must be narrower than the internal dimension of the cabinet, otherwise you won't be able to fit it in. Standard kitchen cabinets have an internal width of 560 mm (60 cm series) or 760 mm (80 cm series). For 90 cm wide sink cabinets, the internal width is usually around 860 mm.
Note: the width of the cabinet and the width of the countertop on it are different things. The countertop usually extends 20–25 mm beyond the front of the cabinet and may be narrowed on one side when connected to a wall or another cabinet.
Step 2 – Measure the countertop (front-to-back dimension)
The front-to-back depth of the countertop (from the front edge to the back edge, including the toe kick at the wall) is usually 600 mm. If you have a non-standard countertop (e.g., 650 mm or 550 mm), this is an important detail – the sink must have a front-to-back dimension smaller than or equal to the countertop, leaving at least 30 mm of free space in front of the cut-out (for the stability of the sink edge).
Step 3 – Check the waste pipe
The position of the waste pipe in the wall or floor determines whether you can use a standard trap or need an extension. A standard trap usually requires 150–200 mm from the bottom of the cabinet to the center of the waste pipe. If your cabinet is low or the waste is high, you need to choose a flat (low) trap. With the sink ATROX 50 černý 91 + pop up sifon, the trap is part of the delivery and its dimensions are clearly defined – that is why it is important to check whether you have enough space.
Step 4 – Determine the thickness of the worktop
The thickness of the worktop affects the choice of mounting brackets. A standard laminated worktop is 38 mm thick, stone and composite worktops can be 20–60 mm thick. With a top-mounted sink (replacement mounting), the thickness of the worktop is important because the mounting brackets must reach the underside of the worktop and at the same time the cutout must be smooth and clean.
Step 5 – Record the position of the faucet hole
If you are replacing an existing sink and want to keep the existing faucet, record the distance between the centers of the faucet holes. The standard distance (spacing) is 35 mm or 150 mm. Some Alveus sinks have pre-drilled slots for the faucet (clickable holes), which you can only grind in the places where you need them.
Typical dimensions of kitchen sinks and which cabinets they fit
In practice, we encounter several standard combinations. The following table is an approximate overview – always check the exact dimensions of the product in its technical specifications:
| Cabinet width | Typical external sink dimensions | Typical cutout dimensions | Note |
|---|---|---|---|
| 45 cm | 420 × 400–480 mm | 380 × 360–440 mm | Small apartments, corner solutions |
| 50 cm | 480 × 480–500 mm | 440 × 440–460 mm | Compact kitchens |
| 60 cm | 580–600 × 480–510 mm | 540–560 × 440–480 mm | Most common dimension |
| 80 cm | 780–800 × 480–510 mm | 740–760 × 440–480 mm | Double bowl or large single bowl |
| 90 cm | 860–900 × 480–510 mm | 820–860 × 440–480 mm | Large double bowl or 1.5-bowl |
| 120–130 cm | 1160–1300 × 480–510 mm | 1120–1260 × 440–480 mm | Double bowl, ideal with an island; e.g. Intermezzo 130/81 |
Replacing an existing sink – the most common scenario in practice
The most common situation we encounter is the replacement of an old sink without replacing the worktop. The customer wants a new sink, the worktop remains. Here are a few rules that can save you a lot of complications in practice:
If the new sink is the same size or larger than the old one
The new sink must have an external dimension larger than the existing cutout, otherwise it will have nowhere to sit. Ideally, the new sink should cover the old cutout by at least 10 mm on each side. When enlarging the cutout (routing), make sure that the cutout does not get closer than 30 mm to the edge of the worktop – otherwise the worktop may crack or break off in that area.
If the new sink is smaller than the old one
This is a much more complicated situation. If the new sink is smaller, the old cutout in the worktop will remain larger than needed. In such a case, you need to either cover the gap with a profile or sealant (not ideal from a hygiene point of view), or replace the entire worktop. We always recommend measuring so that the new sink is at least as large as the old one.
Changing the sink while keeping the faucet
If you are replacing only the sink and keeping the faucet, check the spacing of the holes for the faucet on the countertop (usually 35 mm or 150 mm) and compare it with the holes on the new sink. Many Alveus sinks have pre-drilled slots from which you choose only the necessary ones – the rest will remain covered by a cover strip or sealant.
Undermount installation – different measurements, different requirements
With undermount installation, the sink is attached from below to the countertop and the sink edge is not visible. This method of installation requires more precise measurements and usually also a sturdier countertop (stone, composite, concrete). Reasons:
- The outer dimensions of the sink must be smaller than the cutout in the countertop – the sink is inserted from below upwards and secured with brackets.
- The cutout must be precisely routed according to the outer shape of the sink, because any gap between the edge of the cutout and the sink will be visible from above.
- The countertop must be thick enough to accommodate the brackets – with stone, the brackets are glued with epoxy.
- The edge of the cutout must be rounded (recessed) and sealed with waterproof sealant, otherwise moisture will penetrate into the core of the countertop.
A more detailed installation procedure can be found in the article Installation of Alveus sink step by step – undermount, replacement and built-in installation.
Sink depth – what it affects and what to pay attention to
The depth of the sink (basin height) usually ranges from 150 to 220 mm. Most standard sinks have a depth of 180–200 mm. That sounds simple, but in practice, this measure affects several things at once:
Worktop height and comfort while working
If your worktop is at a height of 90 cm (Slovak standard), then the bottom edge of the sink (basin floor) will be at a height of 90 – 3.8 (worktop thickness) – 18–20 cm (sink depth) = approximately 68–70 cm above the floor. That is quite low. The trap and P-trap must be lower than this height, so they must fit into the cabinet, where you also have the waste pipe and water supply lines.
Basin volume and comfort while washing
A deeper sink holds more water and splashing while washing vegetables or dishes is less. If you have a family with children, or if you like to cook and wash large pots, a deeper basin (190–220 mm) is definitely more comfortable. A shallow sink (150–160 mm) is suitable where the sink is mainly used for washing hands or where the worktop is exceptionally low.
Choosing the right trap
Every sink needs a trap that fits between the bottom of the sink and the bottom of the cabinet. If the cabinet is low (for example, only 60 cm high including the legs), you need a flat trap with a height of up to 120 mm. With higher cabinets (80–90 cm), there is enough space for a standard trap with a height of 150–200 mm. Also think carefully about whether you want a trap with a trap, without a trap, or with a so-called pop-up drain – these variants have different heights.
Sink dimensions for a kitchen island or for a table
The kitchen island is becoming increasingly popular, but it brings different requirements for sink dimensions. In an island, there is usually no wall behind the sink, so the front-to-back dimension of the sink can be larger – but at the same time, you must ensure that the supply pipes (water and waste) are hidden in the island structure or routed in the floor.
An excellent choice for island applications is, for example, SET ALVEUS INTERMEZZO 130/81 + BATERIE TONIA Chrom – it is a large double basin with dimensions of 1300 × 810 mm, which covers a more generous island size. Before ordering, don't forget to check that the internal width of the island is at least 860 mm (so that the sink edge is supported by the worktop from all sides).
Compact solutions for small kitchens and corner sinks
In small apartments, studio flats or office kitchens, space is limited. In such cases, corner or significantly narrower sinks come into play. For example, SET ALVEUS CADIT 40/55 + BATERIE RUTA CHROM has compact dimensions that are suitable for cabinets of width 45–50 cm. With such a sink, it is especially important to measure the front-to-back dimension of the countertop precisely, because with a small sink, the ratio of sink depth to worktop width is greater and the gaps at the edges can be less than 30 mm.
For very small kitchen blocks or where every centimeter really counts, there are also sinks with an external dimension of around 300 mm – such as SET ALVEUS INTERMEZZO 30/91. With these dimensions, however, you need to keep in mind that the faucet must have a sufficiently long spout to reach over the center of the basin – otherwise the water will run over the edge.
Most common mistakes when measuring – what we’ve seen in practice
Over the years of sales and installations, we have seen recurring mistakes that have cost customers unnecessary waiting, extra transportation, or reworking the countertop. Here are the most important ones:
- Measuring the old sink instead of the cutout: A customer measures the bottom of an old sink and assumes that is the dimension they need. But sink size ≠ outer sink dimension ≠ cutout size. Always measure the cutout in the countertop and the outer edge of the sink.
- Forgetting the thickness of the cabinet side panel: The internal width of the cabinet is smaller than its external width by two times the thickness of the board (usually 2 × 18 mm = 36 mm). If you have a 60 cm wide cabinet from the outside, the inside is only 564 mm wide.
- Ignoring the position of the drain pipe: A drain in the center of the wall behind the sink and a drain in the corner of the wall require different types of trap. Some trap types have an outlet on the right, others on the left – this needs to be resolved before purchase, not after installation.
- Not checking the position of the faucet hole: If you replace a sink and the new one has a faucet hole in a different position than the old one, you either need to drill a new hole in the countertop or cover the old one. Both solutions are complicated.
- Underestimating the weight of the sink: Granite sinks can weigh 15–35 kg. Mounting one on its own is a problem, but so is measuring and securing it – a strong worktop holds the sink better than a thin MDF panel.
- Purchasing a sink without verifying the cabinet depth: Some cabinets have a depth of only 400 mm (for example, in a pedestal cabinet or balcony). A standard 510 mm sink simply won’t fit into such a cabinet.
Practical example: Replacing a sink in a panel kitchen
Typical situation: a customer lives in an apartment built in the 80s. The kitchen unit has one 60 cm wide sink cabinet with a flat laminate countertop and no other cutouts. The old stainless steel sink is single-bowl, with an outer dimension of 565 × 495 mm and a cutout in the countertop of 520 × 455 mm. The customer wants an undermount granite sink with a drip tray.
Correct procedure: measure the existing cutout (520 × 455 mm) and the outer edge of the old sink (565 × 495 mm). The new sink must have an outer dimension of at least 565 × 495 mm to cover the old cutout, and at the same time be smaller than the internal width of the cabinet (approximately 564 mm) – almost to the millimeter. In this case, a smarter option would be to enlarge the cutout (if there is enough space in the countertop) and choose a new sink with an outer dimension of approximately 590 × 495 mm, for which the cutout would be increased by 25 mm in width. Before doing so, make sure that at least 30 mm remains from the edge of the cutout to the edge of the countertop.
These detailed installation procedures can also be found in the article Installation of an Alveus granite sink – installation procedure including trap and faucet.
Measuring for a new sink when there is no existing cutout
If you are buying a sink for a new kitchen without a pre-cut countertop (the worktop is still intact or will be cut to size), you have more freedom, but at the same time you must be more precise in your communication with the person who will cut the countertop. The procedure is as follows:
- Select a specific sink model and note its outer dimensions and recommended cutout size (the manufacturer usually specifies this in the product information).
- Provide these dimensions to the carpenter or kitchen studio that will cut the countertop.
- Check the position of the cutout on the countertop – the sink is usually placed closer to the back wall (the rear wall), to leave space in front of the sink. The minimum distance from the front edge of the cutout to the front edge of the countertop is 30–40 mm.
- If the sink has a faucet hole, determine which side you want it on (right, left, center) and note the distance from the center of the hole to the edge of the sink.
- If you plan an undermount installation, inform the carpenter to round the edge of the cutout and seal it with waterproof varnish or silicone before assembling the countertop.
Frequently asked questions (FAQ)
How do I find the recommended cutout size for a specific Alveus sink?
Each Alveus sink has three dimensions listed in the product sheet (PDF) or in the technical table on the product page: total outer dimension, recommended cutout size, and basin depth. If you cannot find these details in the product sheet, the general rule applies: cutout size = outer dimension minus 2 × edge width (usually 20–40 mm on each side). In case of doubts, contact us – we can confirm the exact numbers for you.
Can I buy a sink that is larger than my countertop?
No, that is not possible. The outer dimension of the sink must be smaller than the countertop (the sink must have something to sit on), and at the same time, the front-to-back dimension of the sink must not exceed the depth of the countertop. If you need a larger sink, you must also replace the countertop or use a custom-cut countertop.
What happens if the cutout in the countertop is a few millimeters larger than the sink edge?
If the cutout is larger than the outer dimension of the sink, the sink cannot be installed – it has nothing to rest on and will fall through. If the cutout is only 1–2 mm larger on one side, you can temporarily solve the issue with silicone sealant and shims under the edge, but this solution is not reliable in the long run and we recommend it only as a temporary fix. The correct solution is either a larger sink or a new countertop.
Do I have to replace the trap when replacing the sink?
Not always, but usually yes – we recommend it. The old trap may have a different outlet diameter, different outlet position, or may be worn out. A new sink may also have a different basin shape or an outlet in a different location, which makes it impossible to connect to the old trap. A new trap is relatively inexpensive compared to the overall cost of replacing the sink and faucet.
What does the designation “91" in Alveus product names mean?
The number after the slash in the color designation (e.g., 91 = natural/light gray, 90 = black, 56 = white, etc.) indicates the color variant of the surface, not the dimension. This Alveus system designation is consistent across the entire granite range. Actual dimensions are always listed in millimeters in the product sheet or in the technical table of the product.
Can I install a sink without a cutout – for example, directly on the countertop?
Yes, in so-called topmount installation, the sink sits entirely on the surface of the countertop without a cutout. This method of installation is less common and is practically not used for kitchen sinks, as the sink would be too high and dirt would accumulate under the edge of the sink. However, this principle is used in bathrooms for freestanding basins. For Alveus kitchen sinks, the standard is either drop-in or undermount installation.
Conclusion: Measuring is the foundation, not a formality
When choosing a sink, measuring is as important as choosing the product itself. Correctly measuring the countertop, cutout, cabinet, position of the drain, and faucet hole before purchase will save you unnecessary complications, extra transportation costs, and stress during installation. We recommend preparing a paper sketch with the following values before placing an order: internal width of the cabinet, front-to-back depth of the countertop, dimension of the existing cutout (if any), distance of the drain pipe from the bottom of the cabinet, and spacing of the faucet holes.
If you are unsure about any of the dimensions, compare your values with the technical sheets of selected products in the category Alveus on atria.sk. Most installation problems can be avoided with thorough preparation before placing an order – and this is something no installation team can easily replace for you later, as easily as a few minutes with a measuring tape in your hand.
Do you have a question about this topic?
Having trouble deciding or dealing with a specific situation in your home? Write to us – we are happy to help.