RLC Lawn & Landscape · Free planning tool · Lutz & Tampa Bay
Mulch & Rock Calculator
Find out how much mulch or landscape rock you need, in bags, cubic yards and tons. Add each bed, pick a depth, and see the real amount of hauling and spreading involved before you buy.
1. Your beds
Curved bed? Measure the longest length and the average width. Close is good enough.
2. What you'll need
- Area covered0 sq ft
- Volume (incl. 10% extra)0 cu ft
- Total weight to lift0 lb
- Car or SUV trips from the store0
- Wheelbarrow loads0
- Weed fabric0 sq ft
- Materials at your bag price$0
Estimates only. Bags assume 2 cu ft mulch and 0.5 cu ft rock; weights and work times are typical, not guaranteed. RLC confirms exact quantities on site.
How to calculate mulch or rock
Every landscape material is sold by volume, so the math is the same for mulch and rock: find the square footage of each bed, multiply by the depth in feet, and convert to cubic yards or bags.
Square feet × depth (inches) ÷ 12 = cubic feet · Cubic feet ÷ 27 = cubic yards
Example: a 30 ft × 6 ft front bed is 180 sq ft. At 3 inches deep that is 45 cubic feet, or about 1.7 cubic yards. That works out to 23 bags of mulch, or 90 half-cubic-foot bags of river rock weighing roughly 4,500 pounds. The calculator adds 10% for settling, uneven ground and spillage.
Recommended depth for Florida beds
| Material | Recommended depth | Why |
|---|---|---|
| Pine bark or cypress mulch | 3 inches | Holds moisture and blocks weeds without smothering roots. |
| Refreshing existing mulch | 1–2 inches | Tops up color when a base layer is still in place. |
| River rock (¾"–1½") | 2–3 inches | Covers fabric fully so it stays hidden and in place. |
| Pea gravel or small stone | 2 inches | Small stone packs tighter and needs less depth. |
| Lava rock | 2–3 inches | Very light, so it shifts more in heavy rain. |
Bags or bulk delivery?
| Unit | Covers at 3" deep | Good for |
|---|---|---|
| 2 cu ft bag of mulch | About 8 sq ft | Small beds and touch-ups |
| 0.5 cu ft bag of rock | About 2 sq ft | Small accent areas |
| 1 cubic yard (bulk) | About 108 sq ft | Most full-bed projects; roughly 13.5 bags of mulch or 54 bags of rock |
Past about 2 cubic yards, bags become a lot of lifting: every cubic yard of river rock weighs well over a ton. That is usually the point where Tampa Bay homeowners switch to bulk delivery or have RLC install it.
Tips before you start
- Pull weeds and remove grass before adding material. New mulch over live grass or weeds lets them grow right back through.
- Keep mulch a few inches away from tree trunks, palm bases and your home's foundation.
- Use weed barrier fabric under rock, not under mulch. Mulch breaks down into soil; rock needs a clean separation layer.
- Edging keeps rock out of the lawn and mulch from washing onto walkways during summer storms.
- Not sure which material fits your yard? Compare them in our pine bark mulch vs. decorative rock guide.
Frequently asked questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 standard 2-cubic-foot bags of mulch to make one yard. For 3-cubic-foot bags, it takes 9.
How much area does a yard of mulch cover?
At 3 inches deep, one cubic yard of mulch covers about 108 square feet. At 2 inches it covers about 162 square feet.
How much does a cubic yard of river rock weigh?
River rock weighs roughly 2,500–2,800 pounds per cubic yard, or about 1.3 tons. A half-cubic-foot bag weighs around 50 pounds.
How deep should landscape rock be?
Most decorative rock beds look best at 2–3 inches. Larger stone like 1½" river rock needs the full 3 inches to hide the weed fabric underneath.
Should I put landscape fabric under mulch?
Usually not. Fabric under mulch traps decomposing material on top, where weeds root anyway. Fabric works best under rock and gravel.
Does RLC install mulch and rock?
Yes. RLC Lawn & Landscape removes old material, installs fabric and edging, and delivers and spreads mulch or rock across Lutz, Land O' Lakes, Wesley Chapel, Odessa, Tampa and the surrounding Tampa Bay area. Request a free estimate.