Bags of Limestone Screenings for a 20x18 Patio
How many bags of limestone screenings for a 20x18 patio: at 2 inches deep you need about 60.0 cubic feet, which is 120 bags of the common 0.5 cubic foot size. If your store sells limestone screenings in 50-pound bags instead, figure about 125 bags, since limestone screenings weighs roughly 104 pounds per cubic foot.
Volume and tonnage calculator →Bag count by depth
| Depth | Cubic feet | 0.5 cu ft bags | 50 lb bags (approx.) |
|---|---|---|---|
| 1 in | 30.0 | 60 | 63 |
| 2 in | 60.0 | 120 | 125 |
| 3 in | 90.0 | 180 | 187 |
| 4 in | 120.0 | 240 | 249 |
How to figure it
- Area: 20 × 18 = 360 sq ft.
- Volume: 360 × (2 ÷ 12) = 60.0 cu ft.
- Bags: 60.0 ÷ 0.5 = 120 bags (round up).
Bags or bulk?
A cubic yard is 27 cubic feet, so 60.0 cubic feet is 2.22 yards, about 3.1 tons. At this size, a bulk delivery usually beats a cart full of bags once you count trips. Compare the bag price × 120 against a bulk quote for 3.4 tons delivered.
About limestone screenings
Limestone screenings are the fine dust and chips left after crushing limestone. They pack very tight, which makes them a common setting bed for pavers and flagstone and a surface for paths.
Before you spread for a patio
- Dig and level. Remove sod and set the base slightly below the surrounding grade.
- Edge it. Steel, plastic or stone edging keeps material in place.
- Spread in layers. Rake to depth, then tamp or wet and compact.
- Buy a few extra. Grab 5 to 10 percent more bags for settling and touch-ups.
The volume and tonnage calculator handles other sizes and depths.
When to choose limestone screenings
Good uses:
- Paver and flagstone setting beds
- Firm walking paths
- Top-dressing a compacted stone base
Think twice for:
- Deep layers on their own
- Low spots that collect water
- Under heavy vehicle traffic without a base
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of limestone screenings (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 20x25 area at 3 inches takes about 6.5 tons.
- Weight used here: about 1.4 tons per cubic yard.
Common estimating mistakes
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
Questions people ask
How many bags of limestone screenings for a 20x18 patio?
About 120 bags of 0.5 cubic feet at 2 inches deep.
How many 50 lb bags of limestone screenings for 20x18?
About 125 bags at 2 inches.
How many 0.5 cubic foot bags are in a cubic yard?
54 bags.
How many cubic feet is a 20x18 patio at 2 inches?
About 60.0 cubic feet.
When does bulk make more sense?
Usually once the job passes about a cubic yard, or when you would need more than a few car trips.
Related guides
- #10 Stone (Stone Dust): Size, Uses and How Many Tons
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Much Does a Ton of Gravel Cover? Depth Chart
- Bags of Limestone Screenings for a 20x14 Patio
- Bags of Limestone Screenings for a 20x16 Patio
As an Amazon Associate, AsphaltTons.com earns from qualifying purchases. Product links below are sponsored.