How to use this calculator
- Measure the bed. Length and width in feet — round shapes can be approximated as rectangles.
- Choose depth. Most beds use 2–3 inches; tree rings 3–4 inches.
- Pick bag size. Default is 2 ft³ (most retail bags). Bulk delivery is by cubic yard.
- Read result. You get cubic yards for bulk delivery and exact bag counts for retail buying.
Formula
Volume (yd³) = Length × Width × Depth ÷ 27
Worked example
A 20 ft × 6 ft bed at 3 inches deep equals 1.11 cubic yards (30 cubic feet). That's 15 bags of 2 ft³ mulch or 10 bags of 3 ft³ mulch.
Common project sizes
Quick reference for the most common mulch calculator use cases. Use these as a sanity check on your calculator inputs.
| Project | Dimensions | Result |
|---|---|---|
| Small foundation bed (3×20 ft, 3 in) | 60 ft² | 0.56 yd³ · 8 bags (2 cu ft) |
| Standard front bed (4×40 ft, 3 in) | 160 ft² | 1.48 yd³ · 20 bags · or bulk |
| Backyard borders (300 ft², 3 in) | 300 ft² | 2.78 yd³ · bulk delivery |
| Large landscape (800 ft², 3 in) | 800 ft² | 7.4 yd³ · bulk only |
| Tree ring (5 ft diameter, 3 in) | 20 ft² | 0.18 yd³ · 3 bags (2 cu ft) |
2026 cost reference
Typical retail price range in the United States for mulch. Local pricing varies by region, supplier, and grade — confirm with two or three quotes before ordering.
Per cubic yard (delivered bulk)
$25 – $60
Standard hardwood or double-shredded mulch is $25–$45/yd³ at the supplier, plus $40–$80 delivery. Premium dyed mulch (black, brown, red) runs $40–$60/yd³. Bagged retail is $3–$5 per 2 cu ft bag — equivalent to about $40–$70/yd³ before tax, only worth it for jobs under 1 yd³.
By the numbers — regional pricing
Snapshot of current US pricing for cubic yard (delivered bulk, hardwood double-shredded), broken down by Census region. Source: Average of 20 landscape supplier spot-checks per region; delivery surcharge ($40–$80 typical) excluded.. Data as of April 2026; we refresh quarterly.
| Region | Low | High | Note |
|---|---|---|---|
| Northeast | $32 | $52 | — |
| Midwest | $25 | $42 | Pickup at municipal yards often $15–$20/yd³ if you have a trailer. |
| South | $28 | $48 | Pine bark and cypress more common than hardwood. |
| West | $35 | $60 | Higher than national average due to fire-resistant blend demand. |
How we calculate this
Assumptions baked in
Volume = Area × Depth; cubic yards = Volume in ft³ ÷ 27. Default bag sizes are 2 ft³ (most retail bags) and 3 ft³ (premium bags). Weight per yard is taken from USDA NRCS material density references: shredded hardwood mulch averages 800 lb/yd³ dry, 1,200 lb/yd³ wet. The calculator does not adjust for settling; freshly laid mulch compacts roughly 10–15% in the first month.
Accuracy and margin of error
For rectangular beds, area is exact. For irregular curved beds, divide into rectangles and add an extra 5–10%. Bag-count conversions are accurate per bag; if your bag is labeled 1.5 ft³ or "covers X ft² at 3" deep", trust the label number over our default — bag fill varies by manufacturer.
Edge cases this calculator does not handle
Sloped beds need more mulch than the footprint suggests — use the slope length, not horizontal length. For playgrounds, use the ASTM F1292 / F2075 impact-attenuation depth for the fall height of equipment (typically 6"–9", not the decorative 2–3"). For erosion-prone slopes over 15%, use shredded hardwood (interlocks) rather than nuggets (which roll).
Cited sources for this page
The figures and rules above are anchored to the following normative references. We link the underlying claim to its standard — not as generic SEO trust signals, but so you can audit any number on this page against a primary source.
Engineered wood fiber playground mulch must meet ASTM F2075 for particle size and ASTM F1292 for impact attenuation at the equipment's critical fall height.
Source: ASTM F1292-22 and ASTM F2075-15
Bulk mulch density reference of 800 lb/yd³ for shredded hardwood is from the USDA NRCS Plant Materials Center technical note.
Tips for accurate results
- A 2-inch layer is the minimum for weed suppression.
- Don't pile mulch against tree trunks — leave a 2-inch gap.
- Bulk delivery is typically cheaper than bags above 2 yd³.
- Refresh every spring; replace fully every 2–3 years.
Common mistakes to avoid
- Volcano mulching — piling mulch against tree trunks. Traps moisture and rots the bark within 1–2 seasons.
- Going too deep on annuals (4+ inches) — chokes shallow roots and breeds fungal disease.
- Buying bagged for a project over 3 yd³ — bulk is roughly half the price, and delivery (typically $40–$80) pays for itself fast.
- Mixing fresh and old mulch without raking — the bottom layer compacts and turns water-repellent. Break it up first or you create a moisture barrier.
When to consult a pro
Mulching is the easiest landscape DIY there is — order delivery, ask the driver to dump near the beds, spread with a rake. Hire help only if you cannot lift 50 lb bags or if the delivery truck cannot reach the beds (long carries with wheelbarrows turn into a back-injury risk). For commercial properties, contracts with a landscape company often beat DIY at scale because of bulk-buying power and crew speed.