How to measure your beds
Measure each bed in feet. For rectangular beds, enter length and width. If you have several beds, work out each area, add them together, and use the total area mode. For tree rings, measure the diameter of the mulched circle. For curved or irregular beds, the square footage calculator can help you break the shape into simpler pieces.
Before ordering, check how much old mulch is still there. Push a trowel down in a few spots: if you already have 1 in, you only need to add the difference to reach your target depth.
Worked example: a 10 × 10 ft bed, 3 in deep
With the defaults (mulch, 2 cu ft bags at $5, bulk at $50 per cubic yard, no delivery fee):
| Step | Calculation | Result |
|---|---|---|
| Area | 10 × 10 | 100 sq ft |
| Volume | 100 × 3 in ÷ 12 | 25 cu ft (0.93 cu yd) |
| Bags | 25 ÷ 2 = 12.5 | 13 bags |
| Bagged cost | 13 × $5 | $65 |
| Bulk order | 0.93 cu yd → next ½ yd | 1 cu yd |
| Bulk cost | 1 × $50 | $50 |
Bulk comes out $15 cheaper here, but only if you can pick it up. Add a delivery fee and the bags win at this size. Bulk usually pulls ahead clearly once you need a couple of yards or more, because the delivery fee is spread over more material.
Depth changes everything
The scenario table shows the same bed at 1, 2, 3 and 4 in:
| Depth | Volume | 2 cu ft bags | Bagged | Bulk |
|---|---|---|---|---|
| 1 in | 8.3 cu ft | 5 | $25 | $25 |
| 2 in | 16.7 cu ft | 9 | $45 | $50 |
| 3 in | 25 cu ft | 13 | $65 | $50 |
| 4 in | 33.3 cu ft | 17 | $85 | $75 |
Bulk cost moves in steps because suppliers sell in half-yard increments, while bag cost rises with every bag. That is why the cheaper option can switch back and forth as the depth changes.
For mulch, Penn State Extension recommends 2–3 in. The calculator warns below 2 in, where mulch does little for weeds or moisture, and above 4 in, where it can keep roots from getting air. Keep mulch pulled back a few inches from tree trunks and plant stems; piling it against bark (“volcano mulching”) invites rot and pests.
Mulch, topsoil or compost?
- Mulch sits on top of the soil to hold moisture, moderate soil temperature and smother weeds. It is not mixed in.
- Topsoil fills low spots, builds raised beds and gives new lawns a growing layer. Typical depths are greater than for mulch, often 4–6 in for new lawns or beds.
- Compost is mixed into existing soil or spread as a thin top-dressing to add organic matter. The calculator reuses topsoil prices for compost because compost prices vary widely, so enter your local price.
In the 2026 price data, bulk mulch runs $20–$80 per cubic yard and bulk topsoil $10–$55. The bagged topsoil price is an estimate for 0.75–1 cu ft bags. If you select a larger bag size, update the price to match.
Bags or bulk: practical points
Bags are clean, easy to carry in a car, and let you buy exactly what you need, which helps with small beds or hard-to-reach backyards. Bulk is cheaper per yard but needs a place to dump the pile, a wheelbarrow, and usually a delivery charge (roughly $50–$100 for mulch).
What’s not included
Weed removal, edging, landscape fabric, and labor. For stone ground cover, use the gravel calculator instead. Planning a patio next to the beds? The paver patio calculator covers base, sand and pavers.
How this calculator works
- Area: length × width, a total area you enter, or π × (diameter ÷ 2)² for a circle.
- Volume = area × depth ÷ 12 cu ft; cubic yards = cu ft ÷ 27.
- Bags = ceil(cu ft ÷ bag size). Bagged cost = bags × bag price.
- Bulk cost = cubic yards rounded up to the next ½ yd × bulk price + delivery fee.
Assumptions and limitations
- Default mulch depth is 3 in, the upper end of Penn State Extension’s 2–3 in recommendation.
- Bulk material is ordered in ½ cu yd increments with a ½ cu yd minimum; bags are rounded up to whole bags.
- Default prices are national 2026 typical values. Bagged topsoil price is an editorial estimate for a 0.75–1 cu ft bag. Compost reuses topsoil prices.
- No allowance is added for settling or spillage; add a few percent to the area if your beds are irregular.
These results are planning estimates, not quotes. Local prices, site conditions and building codes vary, so get written estimates from licensed contractors before you commit to a budget.
Try your own numbers. Every price and assumption above is editable in the estimator.
Back to the mulch & soil estimatorFrequently asked questions
How much area does a cubic yard of mulch cover?
How many bags of mulch are in a yard?
Should I remove old mulch before adding more?
Sources and data
- HomeGuide (2026) — mulch prices
- Angi (2026) — topsoil cost
- Angi — mulch calculator
- Penn State Extension — mulching landscape trees
Prices are US national ranges reviewed October 2026 (data version 2026.10). A few values are editorial estimates where no single published source exists; the Cost Index marks each one. Read our methodology and editorial policy.