Worktop Calculator — Kitchen Worktop Lengths & Joints

Standard laminate worktops in the UK come in 3m (3000mm) lengths, typically 600mm deep and 38mm thick. Some suppliers offer 4m lengths. Solid wood, quartz and granite worktops are often templated and cut to exact measurements rather than sold in standard lengths.

Worktop pieces are joined using a mitre joint (for corners) or a butt joint (for straight joins). For laminate worktops, use worktop joining bolts to pull the joint tight, with colour-matched sealant or special jointing compound. The joint should be as tight as possible to prevent water ingress. Mason mitre jigs are available for cutting accurate 45-degree angles.

A standard kitchen worktop should overhang the base units by approximately 25-30mm at the front. This allows doors and drawers to open freely and provides a drip edge. For breakfast bars, allow 300mm minimum overhang for seating, supported by brackets if over 300mm.

Upstands are narrow strips (typically 100mm high) that sit between the worktop and the wall to prevent water and debris from getting behind. They are standard with laminate worktops. Full-height splashbacks (typically 450-600mm, the gap between worktop and wall units) are an alternative. Behind a hob, use a heat-resistant splashback or backing material — fire-retardant material is advised within about 300mm of a burner. Note the 750mm figure often quoted for hobs is the minimum clearance for a cooker hood above a gas hob (650mm above electric/induction), not a splashback height.

For a standard straight run, 5% extra is usually sufficient. For L-shaped or U-shaped kitchens with mitre joints, allow 10% extra as the corner cuts produce more waste. If you are cutting from 3m lengths, consider the off-cuts you will generate and whether they can be used for other sections.

The standard UK kitchen worktop is 600mm deep and sits at around 900mm above the floor (a typical 870mm base unit plus a roughly 150mm plinth, less the cabinet sitting into the floor zone). Laminate worktops are most commonly 38-40mm thick, though slimmer 20-30mm profiles are popular for a modern look, and 12-15mm compact-laminate boards are also sold. Standard length is 3m (3000mm). Wider boards of 620-670mm are sold as breakfast-bar tops and 900-1200mm boards for island and peninsula units. Solid wood, quartz and granite are usually templated and cut to exact size rather than sold in fixed lengths.

In the UK, laminate worktops are most commonly supplied in 3m (3000mm) lengths, the size most kitchen runs are designed around. Longer boards are also widely stocked at roughly 3.6m (3600mm) and 4m to 4.1m (4000-4100mm), useful for long single runs with no mid-run joint. Shorter 2m-2.1m boards exist for compact kitchens. This calculator divides your total measured run (plus your wastage allowance) by the standard length to tell you how many full pieces to order; you can change the standard length under Advanced Options if your supplier uses a different size.

Measure each run separately, keeping the tape tight to the wall, from the corner to the next break point such as an end panel or appliance gap. For L and U-shaped kitchens, split the layout into runs and add the full wall-to-wall length of each (the calculator deducts the shared corner once so the area is not double-counted). Check the depth from the wall to the planned front edge — standard worktop depth is 600mm, allowing roughly a 25-30mm front overhang over 560mm-deep base units. Walls are rarely square, so measure each run at both ends and use the longest reading, and note any sink, hob or appliance cut-outs. For templated stone such as quartz or granite the supplier takes the final measurements; your figures give an accurate ordering estimate.

For dwellings built to the wheelchair accessible standard M4(3), Approved Document M Volume 1 (2015 edition incorporating 2016 amendments), paragraph 3.34, requires a continuous worktop section at least 2200mm long that incorporates the sink and hob and is either height-adjustable or able to be re-fixed at alternate heights, with clear open leg space underneath capable of at least 700mm clearance above floor level. Drainage must suit worktop heights between 700mm and 950mm above finished floor level, the sink must be no more than 150mm deep and insulated, and taps must be lever-operated. Always design accessible kitchens to the current Approved Document M and BS 9266:2013 (the British Standard for accessible and adaptable general-needs housing), not to a standard 900mm showroom height. Note that BS 8300-2:2018 explicitly does not apply to individual dwellings, so it is BS 9266, not BS 8300, that governs a domestic accessible kitchen.