Countertop Calculator
Where the join falls matters more than the total length.
Work out Countertop. Where the join falls matters more than the total length. States the assumption instead of hiding it.
More for a diagonal or patterned layout, more again for an awkward room
Lengths to buy
13 lengths
20 m² net · 23 m² with waste
Worktop is sold in fixed lengths and joins are visible, so the layout decides the count rather than the area. A run longer than the available length needs a join, and a join near a sink or hob is both structurally weak and where water gets in — plan where it falls before ordering.
How the Countertop Calculator works
Worktop lengths needed for a kitchen, with cut-outs deducted and the count rounded up. Worktop is sold in fixed lengths and joins are visible, so the layout decides the answer rather than the area.
Also known as: worktop length calculator · how much kitchen worktop do i need · kitchen counter measurement calculator · where should a worktop join go
Where the join goes decides the layout
Worktop is sold in fixed lengths and every join is visible, so the count is driven by the layout rather than by total area. A run longer than the available length needs a join, and where that join falls is a decision worth making before ordering.
It should not fall near a sink or a hob. A join near water is where the substrate swells and fails first; a join near a hob is weakened by heat cycling and hard to keep sealed. Both are the standard places worktops fail.
A laminate join is made with a masons mitre — a curved cut on a jig, drawn together with bolts from beneath and sealed. A square butt joint across the front edge is much weaker, always visible, and lets water straight into the core.
Material decides how it is measured and cut
Laminate can be measured and cut on site, and scribed to a wall that is not straight. Stone and solid surface are templated after the units are fitted and cut in a workshop, because the tooling and the tolerances are different.
That difference changes the sequence of a kitchen installation. A stone worktop cannot be ordered from a drawing — it is templated once the cabinets are in and level, which adds a wait of a week or more between fitting units and having a usable surface.
Support matters more for stone. It is strong in compression and brittle in bending, so an overhang beyond about 300 mm needs brackets or a supporting substrate. An unsupported breakfast bar overhang cracks at the point of load rather than gradually.
Depth, clearance and the details that get missed
Standard worktop depth is 600 mm, matching base unit depth plus a small overhang past the door fronts — typically 20 to 30 mm, enough to shed spills clear of the cabinet without becoming a knee hazard on a seating side.
Clearance above matters as much. Around 450 to 600 mm to the underside of wall units is comfortable, and above a hob the manufacturer's minimum clearance to an extractor is a safety requirement rather than a preference.
The cut-outs do not change the area — the sink and hob openings come from the same piece — but they do constrain where joins can go. That constraint sometimes forces an extra length, which is the case worth checking before the order is placed.
Where to go next
The Countertop question rarely arrives on its own. These are the ones that usually come with it:
- Cabinet Calculator — Corners eat more frontage than their width.
- Floor Tile Calculator — Buy a spare box — dye lots do not match later.
- Trim and Molding Calculator — Pattern matching adds waste beyond the percentage.
- Ring Size Calculator — Finger measurement to US, UK, EU and Japanese sizes.
Frequently asked questions
How do I measure for a worktop?
Measure each run separately, wall to wall, and allow for the overhang at any exposed end. Add the runs together and divide by the available length, rounding up — a run longer than one length needs a join.
Where should a worktop join go?
Away from sinks and hobs. A join near water is where the substrate swells and fails first, and a join near a hob is both weakened by heat and hard to seal reliably.
What is a standard worktop depth?
600 mm across most of the world, matching standard base unit depth plus a small overhang. Islands and peninsulas often use deeper stock for seating.
How much extra for cut-outs?
None in area terms — the sink and hob openings are cut from the same piece. What they do is constrain where joins can go, which sometimes forces an extra length.
Should I template or measure?
For stone and solid surface, template — the fabricator will make one from the fitted units. For laminate, careful measurement is usually enough because it can be scribed on site.
How much overhang at the front?
Typically 20 to 30 mm past the door fronts, enough to shed spills clear of the cabinet without being a knee hazard on a seating side.
What is a standard worktop thickness?
Commonly 38 mm for laminate and 20 to 30 mm for stone and solid surface. Thicker looks more substantial and weighs considerably more, which matters for the cabinets beneath.
How is a laminate worktop joined?
With a masons mitre cut on a jig, drawn together with bolts from underneath and sealed. A butt joint across the front edge is much weaker and always visible.
Do stone worktops need support?
Overhangs beyond about 300 mm generally need brackets or a supporting substrate. Stone is strong in compression and brittle in bending, so an unsupported overhang cracks at the point of load.
How much clearance above a worktop?
Around 450 to 600 mm to the underside of wall units, and more above a hob where extraction and heat clearances apply. Manufacturer minimums for hobs are non-negotiable.
Can worktops be cut on site?
Laminate yes, with the right blade and care to avoid chipping the surface. Stone and solid surface generally no — they need workshop tooling and are templated after the units are fitted.
How do I protect the join from water?
Seal it properly at installation with the recommended sealant and keep the sink cut-out edges sealed too. Water reaching a chipboard core swells it irreversibly, and that is the usual reason a laminate top fails.
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