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Concrete Countertop Calculator

Free concrete countertop calculator. Enter length, width, and thickness in inches to get cubic feet, 80 lb bags of countertop mix, and slab weight.

Countertop inputs

Enter each dimension in inches. For L-shapes, split the counter into rectangles and add the sections.

Concrete Needed
2.83 ft3
5 bags (80 lb) · 425 lb

How to use this calculator

  1. 1. Measure in inches
    Length along the cabinet run and the counter depth — standard kitchen counters are 25–26 in deep with a 1.5 in overhang.
  2. 2. Set the thickness
    Cast concrete countertops are usually 1.5–2 in thick. At 2 in, a countertop weighs about 25 lb per square foot.
  3. 3. Split L-shapes into rectangles
    Calculate each leg separately and add the results, or use the sections field for identical pieces.

Quick checks

8 ft run @ 25.5 in × 2 in
2.83 ft³ — about 5 bags of 80 lb countertop mix, weighing roughly 425 lb.
6 ft island @ 40 in × 2 in
3.33 ft³ — about 6 bags of 80 lb mix, weighing roughly 500 lb.
4 ft vanity @ 22 in × 1.5 in
0.92 ft³ — about 2 bags of 80 lb mix.