Concrete countertop calculator: how many bags of concrete for a countertop?
7 bags of 80 lb
3.69 cu ft: 29.5 sq ft of top at 1 1/2 in · 0.6 cu ft per bag of Quikrete Countertop Mix · about 7 gal of water · for an L of 10 and 6 ft runs, 25 1/2 in deep
Run your own numbers
Enter it the way you measured it: 4.5, 4 1/2,
3/8 or 10' 6".
7 bags of 80 lb
3.69 cu ft: 29.5 sq ft of top at 1 1/2 in · 0.6 cu ft per bag of Quikrete Countertop Mix · about 7 gal of water
Source: QUIKRETE Countertop Mix No. 1106-80, -81 data sheet: 0.6 cu ft per 80 lb bag, read October 31, 2026. Data sheet (PDF)
An L-shaped concrete countertop with 10 ft and 6 ft runs, 25 1/2 in deep and 1 1/2 in thick, with the corner counted once, is 3.69 cu ft: 7 bags of 80 lb Quikrete Countertop Mix at 0.6 cu ft per bag.
A worked example
One 8 ft 7 in run 26 1/4 in deep and a 6 ft 2 in × 37 in island, both 1 3/4 in thick, with a 1 1/4 in drop edge and a 31 × 19 in sink cutout, needs 9 bags of 80 lb. The run is 18.78 sq ft and the island 19.01, less 4.09 for the sink: 33.70 sq ft at 1 3/4 in is 4.91 cu ft. The drop edge runs 27.08 ft, the front of the run and all four island sides, for 0.41 cu ft more. 5.33 cu ft at 0.6 a bag is 8.9, rounded up to 9.
How thick should a concrete countertop be?
Quikrete's Countertop Mix data sheet gives no thickness, so the calculator takes yours. What thickness changes is bags: one 80 lb bag fills 4.8 sq ft of top at 1 1/2 in, 3.6 sq ft at 2 in and 2.88 sq ft at 2 1/2 in.
What is the Quikrete countertop mix coverage?
An 80 lb bag yields about 0.6 cu ft of mixed concrete, by Quikrete's data sheet. Spread as a top that is 7.2 sq ft at 1 in thick, or 4.8 sq ft at 1 1/2 in; a 2 ft deep top 1 1/2 in thick runs about 2.4 ft per bag.
What are the Quikrete countertop mix instructions?
About 1 gallon per 80 lb bag to start, ending at 8 to 9 pints a bag, mixed at least three minutes to a 5 to 7 in slump. Allow 1 cu ft of mixer per bag, add no more than 20 lb of glass or stone per bag and leave the forms undisturbed for 18 hours or more.
What else it is called
Also searched as a countertop concrete calculator, concrete countertop mix calculator or Quikrete countertop concrete calculator. The bag count is for Quikrete Countertop Mix, a flowable mix made for cast countertops; other mixes print other yields per bag. To pour a floor topping instead, the self-leveling concrete calculator uses a different product.
Bags by countertop shape
| Countertop | 1 1/4 in thick | 1 1/2 in thick | 2 in thick |
|---|---|---|---|
| Straight run, 6 ft (12.8 sq ft) | 3 | 3 | 4 |
| Straight run, 8 ft (17 sq ft) | 3 | 4 | 5 |
| L, 8 + 5 ft (23.1 sq ft) | 5 | 5 | 7 |
| L, 12 + 8 ft (38 sq ft) | 7 | 8 | 11 |
| Galley, two 9 ft runs (38.3 sq ft) | 7 | 8 | 11 |
| Island, 6 ft × 36 in (18 sq ft) | 4 | 4 | 5 |
| Island, 8 ft × 42 in (28 sq ft) | 5 | 6 | 8 |
80 lb bags of QUIKRETE Countertop Mix at 0.6 cu ft each, rounded up. Runs 25 1/2 in deep, the L corner counted once; no drop edge or sink cutout. The data sheet sets no thickness: the three columns are only there to compare.
Where the numbers come from
- Bag yield: QUIKRETE Countertop Mix, product No. 1106-80 (gray) and -81 (tint base), data sheet: "Each 80 lb (36.3 kg) bag of QUIKRETE Countertop Mix will yield approximately 0.6 cu ft (17L) of mixed concrete." The same sheet gives about 1 gallon of water per bag, at least 1 cu ft of mixer capacity per bag, no more than 20 lb of glass or stone per bag, 6000 psi at 28 days, and forms left undisturbed for 18 or more hours. Read October 31, 2026. Quikrete Countertop Mix data sheet (PDF)
- The rest is geometry: top area = each run's length × depth, less one depth × depth corner square where two runs meet in an L, plus the island, less the sink cutout; volume = area × thickness, plus the drop edge as a leg as thick as the slab along the front of the runs and around the island; bags = volume ÷ 0.6, rounded up.
Quikrete's data sheet sets no slab thickness and no reinforcement, so the thickness is yours to enter. In an L both runs are measured along the wall from the outside corner, which puts the corner square in both, so it is taken out once. The drop edge is the extra height below the slab at the front of the runs and on all four sides of an island, its leg as thick as the slab; run ends against a wall get none. For a U, enter the L, then the third run on its own measured from the front edge of the run it meets, and add the two cubic feet before dividing by 0.6.
By Javier Miralles · Last updated . How this site is made.
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