Gravel & Mulch Calculators
Bulk materials are sold by volume, delivered by weight, and installed by depth: three unit systems, one order. The volume math is exact (one yard covers 324 square feet at an inch). The weight bridge is not: density swings 15 percent either way with moisture and stone type, so any site quoting exact tonnage is inventing precision the quarry scale will overrule. Here the volume is exact and the tonnage is a labeled band.
Not Sure Where to Start?
Gravel Calculator (Cubic Yards) is the one most people need. Yards is the unit the supplier quotes, so start with the yards tool. The bag, ton, and specialty versions all reuse the same 324-rule math.
Gravel by the Yard, Foot, or Ton
The 324-rule with compaction allowances, #57 stone specifics, and the French-drain trench case.
- Gravel Calculator (Cubic Yards)Convert your gravel area to cubic yards instantly: yd³ = sq ft × depth ÷ 324. Honest tonnage bands (density varies ±15%), bag counts, and sourced assumptions.
- Gravel Calculator: Cubic FeetGet gravel volume in cubic feet for small jobs like planters or post holes, using the same area-times-depth math suppliers use for yardage, in a smaller unit.
- #57 Gravel CalculatorFigure #57 gravel volume for a compacted driveway or drain base, with the standard 10-20% compaction allowance and a labeled tonnage band, not a guess.
- French Drain Gravel CalculatorSize the gravel envelope around a perforated drain pipe from trench length, width, and a 12-inch depth default, with fabric-lining and compaction notes.
Mulch
Bags versus bulk, playground fall-zone depths, and rubber mulch's very different coverage math.
- Mulch Calculator: BagsConvert your bed area into 2-cubic-foot mulch bags: 13.5 bags per cubic yard, whole-bag rounding, and the depth that actually determines your count.
- How Many Bags of Mulch Do I Need?Answer the bag question directly: enter your bed size and depth and get a whole-bag count of 2-cubic-foot bags, built on the 13.5-bags-per-yard conversion.
- Playground Mulch CalculatorCPSC guidance recommends 9 inches of loose-fill wood mulch for fall protection under play equipment. Size that depth here, plus a compression allowance.
- Rubber Mulch CalculatorRubber mulch sells in 0.5 cu ft bags by weight, not volume: convert your bed area and depth into a bag count here, with a note on migration and durability.
What the Prices Are Doing
At the producer level, sand, gravel & crushed stone costs 6.2% more than a year ago, paving mixtures & blocks 6.6% more (BLS Producer Price Index, July 2025 to July 2026, unadjusted 12-month change). Crushed stone moves slowly but hauling doesn't, and delivery is often the biggest line on a small bulk order. Fewer, fuller loads beat repeat trips. Full picture on the Cost Index.
| Item | Sampled price |
|---|---|
| Vigoro 2 cu ft Shredded Mulch | $3.33 / bag |
| Earthgro 1.5 cu ft Shredded Mulch | $3.97 / bag |
| Pavestone 0.5 cu ft Paver Base | $6.47 / bag |
| Vigoro 0.5 cu ft Pea Gravel | $5.97 / bag |
| SAKRETE All-Purpose 60 lb Gravel | $8.44 / bag |
Worth Reading First
Every calculator above ships with externally validated test values and sourced assumptions. See the methodology page for the full ledger.