Countertop Calculator – Square Footage & Cost | CalcLoft
Find out how many square feet of countertop you need for granite, quartz or laminate — straight, L-shaped and U-shaped layouts, with slab count and cost estimate.
How to measure countertops
Countertop suppliers price stone and laminate by the square foot, so the job is simple: measure every rectangular run of countertop and multiply its length by its depth. Add the runs together to get the total area.
Countertop area = (Run 1 length × depth) + (Run 2 length × depth) + …
A straight galley or single-wall kitchen is just one rectangle. For an L-shaped or U-shaped layout, split the countertop at each inside corner into separate straight runs and measure each one — do not try to measure around the corner curve. Add a small amount for the overhang: standard base cabinets sit 24 in deep (2.0 ft), and tops typically overhang the cabinet face by about 1–1.5 in, giving roughly 25.5 in (2.125 ft) edge to edge. Use whichever depth your fabricator bills, and apply the same rule to every run.
Countertop square footage by layout
The figures below assume a standard 2 ft (24 in) depth. They are a planning guide only — every kitchen floor plan is different.
| Layout | Approx. square footage |
|---|---|
| Straight galley (12 ft run) | 24 sq ft |
| L-shaped (10 + 4 ft runs) | 28 sq ft |
| L-shaped (12 + 5 ft runs) | 34 sq ft |
| U-shaped (three runs) | 40–50 sq ft (typical 44) |
Islands, peninsulas, corner sinks and extra depth all change the total, so measure each run of your own kitchen instead of assuming a size.
How many square feet is one slab of countertop?
A full granite or quartz slab is usually about 9–10 ft long and 5 ft deep, which yields roughly 50 sq ft of usable material after edges are trimmed. Marble, quartzite and sintered stone slabs vary by manufacturer and lot. The calculator rounds the area up in steps of 50 sq ft as a planning estimate — confirm slab yield and pricing with your fabricator before ordering.
Related guides
Countertop calculator FAQ
How do I measure an L-shaped countertop?
Split the layout at the inside corner into two straight runs. Measure each run separately (length × depth), then add the two areas together. Do the same for a U-shaped kitchen — treat each of the three walls as its own run and add them all up.
Should I use 24 in or 25.5 in for the depth?
Use 24 in (2.0 ft) when you are sizing off the standard base-cabinet footprint. Use 25.5 in (2.125 ft) when the tops include the full 1–1.5 in overhang and your fabricator measures edge to edge. Pick one rule and apply it to every run so the total stays consistent.
How big is one slab of countertop?
A full granite or quartz slab is typically about 9–10 ft × 5 ft, or roughly 50 sq ft of usable surface after trimming. Slab sizes differ by manufacturer and lot, so treat the calculator's slab count as a planning estimate and confirm with your supplier before ordering.
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