Solverly

Mulch Calculator

Plan garden beds and refreshes without guesswork—this tool estimates coverage by turning bed dimensions and target depth into practical quantities like cubic yards and bag counts. It’s handy for spring top-ups, new plantings, or curb-appeal projects where you want enough material for full coverage without overspending.

The Mulch Calculator lets you set a desired depth, account for waste/settling, and choose your preferred units so you can size an order with confidence. The goal is a clear, ready-to-buy estimate that streamlines pickup or delivery, keeps costs predictable, and helps you finish the job in one trip. Enter your bed details below to see exactly how much to purchase.

Calculate mulch bags or yards needed by area and depth — with coverage table and optional cost.

Enter bed details

Two cubic feet is common at garden centers.

Optional buffer for post-spread settling.

Optional cost inputs

Quick breakdown

Area (ft²)
144
Depth (in)
3
Cubic yards
1.47
Bags (2 cu ft)
20
Coverage per bag @ depth
8.00 ft²
Estimated cost
—

Coverage table for 2 cu ft bags

DepthCoverage / bagBags for area
2"12 ft²12
3"8 ft²18
4"6 ft²24

Coverage varies with chip size and moisture. Round up to prevent a short second trip.

Results interpretation

We convert bed area and depth to cubic feet, add an optional settling allowance, and show both bags (for your chosen bag size) and cubic yards for bulk orders. The coverage table helps compare depths quickly when we’re on the fence.

  • Depth: 2–3 inches for most beds; 3–4 inches for trouble spots or heavy sun.
  • Bags vs bulk: Bags are convenient in small spaces; bulk wins on price for larger beds.
  • Rounding: We round bags up to whole numbers; yards display to two decimals for supplier quotes.

How it works

Our math keeps units explicit so we can sanity-check each step.

Formulas, steps, assumptions, limitations

Area: Either length × width or a direct ft² input.

Depth: Inches ÷ 12 → feet.

Volume (ft³): area_ft² × depth_ft.

Settling: ft³_loose = ft³ × (1 + allowance%).

Cubic yards: yd³ = ft³_loose ÷ 27.

Bags: bags = ⌈ft³_loose ÷ bag_size_cu_ft⌉.

Coverage per bag: bag_size_cu_ft ÷ depth_ft.

Limits: Organic mulches vary in moisture and chip size; slopes and edging losses aren’t modeled.

Use cases & examples

Front border refresh

24×6 ft bed at 3″, 2 cu ft bags, 10% settling. We get a clean bag count and a yardage equivalent to compare with bulk delivery.

New vegetable beds

Three 10×4 ft beds at 2″. Enter total area (120 ft²) in one pass, then use the table to see how many bags a 3″ layer would need next season.

Play area top-up

Add 2″ over 400 ft² with 3 cu ft bags to reduce trips. If a yard price is favorable, the bulk option shows an immediate comparison.

How to estimate mulch for a bed

We keep the steps practical: measure, pick a depth, choose bags or bulk, add a small allowance, then review both bags and cubic yards.

  1. Measure length × width or calculate a total bed area in square feet.
  2. Choose a target depth in inches (2–4 inches for most beds).
  3. Pick a bag size in cubic feet or plan to order in cubic yards.
  4. Add a small settling allowance if desired.
  5. Review the results in bags, cubic yards, and a quick coverage table.
Tools
  • Measuring tape or wheel
  • Notepad or our page’s Copy link feature
Supplies
  • Mulch
  • Optional edging and rake for clean lines

Tip: If we’re splitting areas by depth (e.g., 2″ around plants and 3″ over bare soil), run separate passes and sum the results.

FAQ: Planning mulch orders

How deep should we spread mulch?
Beds and borders are typically 2–3 inches. Heavier weed suppression or moisture retention can use 3–4 inches. Keep mulch a few inches away from trunks and stems.
What bag size is most common?
Two cubic feet is the most common retail bag size, but 1, 1.5, and 3 cu ft bags are also sold. We let you choose any of these.
Should we order mulch in yards instead of bags?
Bulk is usually cheaper for larger projects (often 3+ cubic yards). Small projects are convenient with bags. Our results show both so we can compare.
Do we need a settling allowance?
Mulch can settle by 5–15% depending on chip size and moisture. We include an optional percentage to add to the volume.
Why do our totals differ from the garden center chart?
Coverage charts use round numbers and assume uniform spreading. Bed edges, curves, and contours change real coverage. Treat our totals as a planning baseline and round up when in doubt.
Can we mix depths across one bed?
Yes. Run separate passes for different zones (e.g., 2 inches around perennials and 3 inches over bare soil) and combine the results.

Mulch planning that balances coverage, cost, and care

We approach mulch like a small construction project: measure carefully, choose a depth with intent, and order once. That keeps weeds down, moisture in, and weekends free.

Pick a depth with a purpose

Two inches suits tidy, well-planted beds. Three to four inches helps with weed pressure and hot summers. Around perennials, stay a couple of inches off stems to avoid rot.

Bags for convenience, bulk for value

When beds are small or access is tight, bags shine. For larger beds, bulk usually wins—especially if we can accept a single delivery window.

Settling happens

Organic mulches compress and dry out. A modest allowance avoids thin spots later without meaningfully overspending today.

Edges, curves, and real life

Bed shapes aren’t perfect rectangles. We round cautiously upward and keep an extra bag or two on hand for touch-ups and high-visibility borders.