What does 184.35 cubic yards of rye hull mulch mean?
It means a 18100 square foot bed, once the 10% waste allowance is added, needs 19,910.00 square feet of cover at 3 inches deep — 4,977.50 cubic feet, which is 184.35 cubic yards. Because mulch is sold by the whole yard, you order 185 cubic yards: the exact figure sits 0.65 yards below the next whole yard, so the order carries 0.65 yards of headroom for spillage and uneven ground. At 3 inches, one cubic yard covers 108.0 square feet, so the same bed at 2 inches would need only 122.90 yards, and at 4 inches it would need 245.80 yards.
Output · formula · meaning
| Output | Formula | What it means |
|---|
| Area needed | area × (1 + waste ÷ 100) | 19,910.00 sq ft — 18100 × 1.10. |
| Volume in cubic feet | area needed × depth ÷ 12 | 4,977.50 cubic feet — 19,910.00 × 3 ÷ 12. |
| Exact volume | area needed × depth ÷ 324 | 184.35 cubic yards — 19,910.00 × 3 ÷ 324. |
| Order quantity | round exact volume up to a whole yard | 185 cubic yards — the next whole yard above 184.35. |
| Coverage per yard | 324 ÷ depth | 108.0 sq ft per yard — 324 ÷ 3. |
| Area behind a target volume | target volume × 324 ÷ depth ÷ (1 + waste ÷ 100) | 18100 sq ft — 184.35 × 324 ÷ 3 ÷ 1.10, rounded. |
| Depth behind a target volume | area needed × depth ÷ 324, solved for depth | 3 inches — the depth that turns 19,910.00 sq ft into 184.35 yards. |
| Waste behind a target volume | target volume × 324 ÷ depth ÷ area − 1, as a percent | 10% — the allowance that turns 18100 sq ft into 19,910.00 sq ft. |
Three things to check before you trust the number
First, measure the bed honestly: length times width for each bed, added together, with L-shaped beds split into rectangles. A guessed area moves the order by the same percentage as the guess. Second, keep the depth honest: rye hulls are slender and papery, so they lay into a dense layer that holds moisture well, but a dense layer thins as it settles and the thin spots need topping up through the season. Third, do not skip the waste allowance on rye hull: even well-laid rye hulls scatter at the edges, and spillage and uneven ground still eat into the load, so the 10% allowance is the difference between finishing the bed and running short with the truck already gone. The headline order of 185 yards carries 0.65 yards of headroom, which covers ordinary spillage on a bed like this one. The rye hulls themselves are hulls left after the rye harvest — the mulch comes from the field, not from timber.
Worked example
Area 18100 sq ft, depth 3 inches, waste 10%. Area needed: 18100 × 1.10 = 19,910.00 sq ft. Exact volume: 19,910.00 × 3 ÷ 324 = 184.35 cubic yards. Order: round 184.35 up to 185 cubic yards. Drop the waste to 0% and the exact volume falls to 167.59 yards, order 168; raise the waste to 5% and it is 175.97 yards, order 176; raise it to 15% and it is 192.73 yards, order 193. Drop the depth to 2 inches and it falls to 122.90 yards, order 123; raise it to 4 inches and it climbs to 245.80 yards, order 246. Depth moves the answer faster than waste does, because every inch adds a full layer across the whole bed.
Rye hull mulch lookup table
Every row below applies 10% waste to the area first, then divides by 324: yards = area needed × depth ÷ 324, rounded up to the next whole yard for the order. Find your bed size and depth, read across, and order the last column.
| Area (sq ft) | Depth (inches) | Area needed (sq ft, 10% waste) | Exact (cubic yards) | Order |
|---|
| 300 | 2 | 330.00 | 2.04 | 3 cubic yards |
| 300 | 3 | 330.00 | 3.06 | 4 cubic yards |
| 600 | 2 | 660.00 | 4.07 | 5 cubic yards |
| 600 | 3 | 660.00 | 6.11 | 7 cubic yards |
| 800 | 3 | 880.00 | 8.15 | 9 cubic yards |
| 800 | 4 | 880.00 | 10.86 | 11 cubic yards |
| 1100 | 2 | 1,210.00 | 7.47 | 8 cubic yards |
| 1100 | 3 | 1,210.00 | 11.20 | 12 cubic yards |
| 1300 | 2 | 1,430.00 | 8.83 | 9 cubic yards |
| 1500 | 3 | 1,650.00 | 15.28 | 16 cubic yards |
| 1600 | 3 | 1,760.00 | 16.30 | 17 cubic yards |
| 1600 | 4 | 1,760.00 | 21.73 | 22 cubic yards |
| 1800 | 2 | 1,980.00 | 12.22 | 13 cubic yards |
| 2200 | 3 | 2,420.00 | 22.41 | 23 cubic yards |
| 2600 | 3 | 2,860.00 | 26.48 | 27 cubic yards |
| 3200 | 2 | 3,520.00 | 21.73 | 22 cubic yards |
Every branch, checked
A 18100 square foot bed at 3-inch depth with 0% waste gives 167.59 cubic yards exact, order 168 cubic yards. The same bed at 2-inch depth with 10% waste gives 122.90 cubic yards exact, order 123 cubic yards. A 18000 square foot bed at 3-inch depth with 10% waste gives 183.33 cubic yards exact, order 184 cubic yards. The same bed at 4-inch depth with 10% waste gives 245.80 cubic yards exact, order 246 cubic yards. Each branch changes exactly one input, so the difference from 184.35 isolates that input.
The reverses, worked backwards
The area behind 184.35 cubic yards is 18100 sq ft: at 18000 sq ft the figures are 183.33 cubic yards exact, order 184 cubic yards, and at 18200 sq ft they are 185.37 cubic yards exact, order 186 cubic yards. The depth behind 184.35 cubic yards is 3 inches: at 2 inches the figures are 122.90 cubic yards exact, order 123 cubic yards, and at 4 inches they are 245.80 cubic yards exact, order 246 cubic yards — one inch either way moves the order by about 61.45 yards. The waste behind 184.35 cubic yards is 10%: at 5% the figures are 175.97 cubic yards exact, order 176 cubic yards, and at 15% they are 192.73 cubic yards exact, order 193 cubic yards.
What the defaults assume
The defaults assume a flat 18100 square foot bed, a uniform 3-inch layer, and a 10% waste allowance. Real rye hull beds are rarely flat: paths and tree trunks eat into the area, and rye hulls at the edges wash into the lawn, so measure the planted area only and keep the waste allowance on sloped ground. Zero square feet is the honest edge: 0.00 cubic yards exact, order 0. A depth of zero or below, a negative area, or a negative waste allowance is rejected, because none of them describes a real bed.
Who uses this
A gardener dressing beds and paths with rye hull: the 18100 square foot headline is a large garden bed or a long drive, and the table covers everything from a 300 square foot border to a 3200 square foot yard. A landscaper quoting a rye hull job: the waste column protects the quote, and the order column is the number given to the supplier. A homeowner laying rye hull on a path: the 3-inch rows are the bed depths, and the 2-inch rows are the path depths. A community garden coordinator splitting a bulk delivery: each plot reads its own row, and the orders add up to the truckload.
Accuracy & limitations
The arithmetic is exact for the inputs entered; the judgement is in the inputs. A guessed area, a depth measured before the rye hulls settle, or a skipped waste allowance will each move the answer by exactly the amount of the error, every load. The model does not include hull washing at the edges, delivery minimums, or the gaps between rye hulls — a supplier may sell only in whole yards or charge extra below a minimum, so confirm the order quantity with the supplier. This page is a calculation tool, not landscaping advice.
Cite this calculator
Rye hull mulch 18100 sq ft at 3-inch depth with 10% waste needs 19,910 sq ft, 184.35 cubic yards exact, order 185 yards. Free calculator, plus 16 rows. Source: Bright Side Kit, https://brightoolbox.com/rye-hull-mulch-chart/, accessed 1 November 2026 (2026-11-01).
Frequently asked questions
Why does the table apply waste to the area first?
Because waste is lost cover: spillage, scattering and uneven ground mean you need more covered area than the bed measures. Adding 10% to the area, then converting to yards, keeps the waste in the same units as the bed. Applying it after the conversion gives the same number here, but the area-first order keeps the table readable.
How deep should rye hull mulch really be?
Three inches is the standard bed layer on this page, and 2 inches suit paths and top-ups. Rye hulls are slender and papery, so a 3-inch spread settles and thins over the season; if thin spots appear, top them up rather than re-laying the whole bed.
Does rye hull mulch introduce weed seeds?
Rye hulls are organic, so a load can carry a few weed seeds; weeds can still root in the dust and debris that collects on top of it, so use fabric underneath and clear the debris. This calculator prices volume only and does not judge the gardening choice.
What if my bed is not a rectangle?
Split it into rectangles, measure each, and add the areas before entering the total. A circle uses radius times radius times 3.14. Guessing one number for an irregular bed is the most common reason orders come up short.
Why order 185 yards when the exact figure is 184.35?
Because mulch is sold by the whole yard, and 184.35 rounds up to 185 — the order carries 0.65 yards of headroom for spillage and uneven ground. That headroom is the buffer the exact figure does not have.
Can I use this chart for other mulch types?
The volume math is the same for any loose mulch — area, depth and waste convert the same way — but settling and coverage differ by material. Rye hulls settle as their hulls break down, so use the rye hull rows for rye hull and the matching chart for stone or wood chips.