Mulch Calculator — ToolWitty
Free tool
Mulch Calculator
How much mulch your beds need — cubic yards, bag count, and bulk vs. bagged cost, by mulch type.
1Bed size
ft
ft
ft
sq ft
2Mulch type & pricing
$/yd³
$/bag
Bags ⇄ cubic yards converter
bags
One cubic yard = 27 cu ft = about 13.5 standard 2-cu-ft bags.
Enter your bed size to calculate.
Breakdown
Bulk cost by mulch type
For your exact bed and depth:
Step-by-step math
How it works
The landscaper’s shortcut worth memorizing — the “324 rule”: one cubic yard covers about 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, or 108 sq ft at 3 inches.
| Situation | Recommended depth |
|---|---|
| New flower / shrub beds | 2–3 inches |
| Weed suppression | 3–4 inches |
| Around trees (mulch ring) | 2–3 inches, kept off the trunk |
| Vegetable gardens | 2–3 inches (lighter for seedlings) |
| Paths and play areas | 3–4 inches |
Order bulk by the half-yard and round up — a little extra beats a second delivery. Keep mulch 2–3 inches away from stems and trunks (the “mulch volcano” kills trees), and remember fresh mulch settles 20–30% in the first weeks.
Related tools
|—|
| New flower/shrub beds | 2–3 inches |
| Weed suppression | 3–4 inches |
| Around trees (mulch ring) | 2–3 inches, kept away from trunk |
| Vegetable gardens | 2–3 inches (lighter for seedlings) |
| Playgrounds (rubber/wood) | Per safety surfacing guidelines |
Too little mulch won’t suppress weeds or retain moisture; too much (over 4 inches) can suffocate roots and encourage rot. Never pile mulch against stems or tree trunks — the infamous “mulch volcano” kills more trees than drought.
Bulk vs. Bagged Mulch: Which Is Cheaper?
As a rule of thumb, bulk mulch is 25–40% cheaper than the equivalent amount in bags once you need more than about 2 cubic yards. Bulk also means less plastic waste. Bags win for small touch-ups, hard-to-reach beds (no wheelbarrow access), and when you want exact color matching from a branded product. The calculator’s side-by-side cost comparison makes the trade-off obvious for your specific project.
Mulch Types Compared
- Shredded bark — the all-rounder; mats together nicely, good moisture retention, mid-range price.
- Hardwood mulch — dense and long-lasting; slightly cheaper than bark in many markets.
- Cedar mulch — naturally insect-repellent and aromatic; premium price.
- Dyed mulch (black/red/brown) — colorfast for a full season; costs a bit more than natural.
- Pine bark nuggets — chunky, slow to break down; great for slopes where washout is a concern.
- Rubber mulch — does not decompose (good for playgrounds); by far the most expensive per yard.
Tips for Ordering and Spreading Mulch
- Always round up. Mulch settles 20–30% in the first weeks, and running short mid-job is the most common mistake.
- Ask about delivery minimums. Many suppliers require a 2–3 yard minimum for free or flat-rate delivery.
- Measure twice. Walk the beds with a tape measure rather than eyeballing — most people underestimate area by 20% or more.
- Re-mulch annually. A 1-inch top-up each spring maintains depth as the old layer decomposes (which, happily, feeds your soil).
- Edge first. Cut a clean bed edge before spreading so mulch stays put and looks professional.
Disclaimer
Prices shown are typical U.S. averages for estimation only and vary by region, supplier, and season. Always confirm current pricing and delivery terms with your local supplier before ordering.