How to Measure for a Kitchen Sink in a UK Kitchen

How to measure for a kitchen sink: prepare your measurements

Gather a tape measure marked in millimetres, a straightedge, a pencil and a sheet for recording dimensions. Note whether you are replacing an existing sink or planning a new worktop opening, and identify whether the current installation is inset, undermount or another type. Photograph the sink from above and the cabinet below before moving anything. These images will help you locate the tap, waste, clips and any obstacles when comparing products.

Write down each measurement with a label rather than relying on a single overall size. For example, record the cabinet's clear internal width separately from the visible width of its front opening. Measure twice, starting the tape from the same reference edge each time, and use the smaller measurement where a gap varies. Do not order from a product's nominal size alone: obtain the installation drawing for the exact model and fitting method.

• Record all dimensions in mm.
• Identify the current sink and fitting type.
• Keep photographs of the worktop and cabinet interior.

Measure the sink base cabinet

Open the doors and measure the clear width between the cabinet's inside side panels. Measure at the front and rear, because fixings or cabinet construction may reduce the usable space. Next, measure clear depth from the inside front edge to the back panel or the nearest obstruction. Record clear height from the underside of the worktop to the cabinet floor, taking shelves and bins into account.

Compare these clear dimensions with the proposed sink's bowl and fitting dimensions, not just its outside rim. A sink may sit over the cabinet sides while its bowl, clips or fixing rails need room inside them. If a central stile, support rail or adjacent cabinet occupies the intended space, mark its position and dimensions. Do not assume a cabinet described as a particular nominal width has that much clear space inside.

• Clear width at the front and rear.
• Clear depth and height.
• Positions of rails, shelves and other obstructions.

Measure the worktop and any existing opening

For a replacement, measure the visible sink from left to right and front to back, then measure the actual cut-out separately if its edges are accessible from below. Check both directions at more than one point and note any irregular corners. An inset sink's visible rim normally extends beyond its cut-out, so the two measurements are not interchangeable. Record the distance from the opening to the worktop's front and back edges and to any joint or end.

For a new opening, measure the usable worktop area and mark the proposed sink position without cutting. Check the available space on each side, including clearance for a tap, draining board, splashback and nearby appliances. Measure the worktop thickness and note its material, as fixing details can vary. Use the exact sink's installation drawing or supplied template to establish the cut-out size, corner shape and required edge distances.

• Visible sink width and depth, if replacing.
• Actual cut-out width and depth, where accessible.
• Distances to worktop edges, joints and obstructions.

Check bowl depth and the space underneath

Measure the proposed bowl's outside depth from the worktop level to its lowest point, using the manufacturer's drawing where possible. Then look below the current sink and record the positions of shelves, bins, appliance hoses and any cabinet back panel. Include space for the waste fitting and its connection to the existing pipework. A bowl that fits the worktop opening can still clash with a drawer or make the waste connection impractical.

If you are replacing a sink, compare the new bowl positions with the old ones rather than comparing only the overall widths. A different bowl layout can put a waste outlet over a cabinet divider or close to an appliance. Check whether clips or other fixings need access from below and whether you can reach them after the sink is in place. Mark any obstruction on a simple sketch with measurements from the cabinet sides and rear.

• Bowl depth below worktop level.
• Waste outlet positions.
• Access for fittings, shelves and stored items.

Locate the tap, water supplies and waste

Record whether the tap is fitted through the sink or the worktop, and measure its position from two fixed edges. If the proposed sink has a tap hole, check its position and the available space behind the tap for its base and handle movement. Where a tap hole must be made in the worktop, confirm the required diameter and positioning from the tap instructions. Do not assume that a replacement tap will use the existing hole without checking.

Photograph the hot and cold supplies, isolating valves, trap and waste pipe beneath the sink. Measure the positions of the waste pipe and any appliance connections relative to the cabinet sides and the underside of the worktop. UK sink wastes and traps are commonly sold with 40 mm waste connections, but fittings vary, so match the actual components and the proposed sink's outlet specification. If relocating pipework is necessary, establish what work is involved before ordering.

Compare the measurements with the exact sink

Create a short comparison using the exact model's overall width and depth, recommended cabinet size, bowl dimensions, cut-out dimensions and fitting instructions. Check each against the measurements you recorded, including the narrowest cabinet width and the smallest relevant edge clearance. Confirm that the proposed fitting type suits the worktop and any existing opening. A product photo cannot establish whether its fixing clips, seal or bowl will fit your installation.

For an inset replacement, check that the new rim covers the entire existing opening while leaving enough material for the specified fixing and seal. For an undermount sink, check the manufacturer's opening shape, support and fixing requirements; a similar overall size does not guarantee a matching cut-out. If any required dimension is missing from the listing, request the installation drawing from the retailer or manufacturer. Record the model number and drawing revision you used so the final order can be checked against them.

• Match the exact model number to its drawing.
• Check the cut-out and fixing space separately.
• Confirm tap, bowl and waste positions.

Verification checklist before ordering or cutting

Read back your measurements in millimetres and check that each has a clear start and end point. Repeat the cabinet's narrowest clear width, the worktop opening dimensions and the distances to nearby edges. Compare those figures with the exact sink's current installation drawing, including any stated tolerances or minimum clearances. Ask the installer to review the measurements if the worktop is already cut or the available margin is small.

Before ordering, check that the bowl and fixings clear everything below, the tap can operate freely and the waste can connect without an unplanned obstruction. Confirm that the sink type suits the worktop and that you have identified any plumbing changes. Keep your labelled sketch, photographs and product drawing together for the installer. Only mark or cut a worktop using the instructions for the sink that will actually be fitted.

• Cabinet, worktop and cut-out measurements repeated.
• Exact model and installation drawing checked.
• Tap, waste and under-sink clearance confirmed.
• Photos and labelled sketch retained.

Scope and limitations

This note helps householders organise measurements and understand the calculation. It does not replace an on-site decision by a designer, installer, contractor, or manufacturer. Fabrication, structure, electrical work, gas, waterproofing, and personal safety require suitably qualified verification.