Mulch Calculator
Estimate cubic yards or 2-cubic-foot bag count for mulch — hardwood, cypress, pine bark, rubber — with coverage tables and cost estimates for typical garden projects.
Mulch Calculator
Enter project dimensions below — results update instantly. Switch units freely.
Estimates assume typical industry density and waste factors. Always verify with your supplier and local building code before purchasing material.
The 3-Inch Rule — and When to Break It
Professional landscapers apply mulch 2 inches thick for new beds, 3 inches for established beds, 4 inches for erosion-prone slopes. More is not better — deeper mulch suffocates plant roots and creates fungal problems.
The classic mistake: piling mulch up against tree trunks (‘volcano mulch’). Traps moisture against bark, promotes rot and pest infiltration. Leave 2-3 inches clear around every stem.
Mulch depth by application:
- New planting — 2 inches (seedlings need light)
- Established ornamental beds — 3 inches
- Tree rings — 3-4 inches, kept off the trunk
- Slope erosion control — 4 inches with jute netting on 20%+ grades
- Playground surface — 6-12 inches engineered wood fiber or rubber
- Winter mulch — 4-6 inches over perennials, remove in spring
Mulch Volume Math & Bag Conversion
Standard mulch bag = 2 cubic feet. Conversions:
- 1 cubic yard = 27 cubic feet = 13.5 bags of 2-ft³
- A bag covers ~8 ft² at 3 inches deep
- 1 cubic yard covers ~108 ft² at 3 inches deep
Mulch price break-even:
- Bags at $4-6 each: ~$54-81 per cubic yard equivalent
- Bulk at landscape supplier: $28-55 per cubic yard delivered
- Bulk is cheaper if you need more than 5 bags (about 0.4 yd³)
Bags win for tiny projects (<5 bags), apartments without garage space, or premium dyed mulches unavailable in bulk.
| Depth | ft² per yd³ | ft² per 2-ft³ Bag | Bags per yd³ |
|---|---|---|---|
| 1 in | 324 ft² | 24 ft² | 13.5 |
| 2 in | 162 ft² | 12 ft² | 13.5 |
| 3 in | 108 ft² | 8 ft² | 13.5 |
| 4 in | 81 ft² | 6 ft² | 13.5 |
| 6 in (playground) | 54 ft² | 4 ft² | 13.5 |
Standard mulch bag = 2 cubic feet. Coverage is direct math from volume; does not vary by mulch type (hardwood, cypress, pine bark all volume-equivalent).
| Type | Lifespan | Color | Best Use | Cost/yd³ Bulk |
|---|---|---|---|---|
| Hardwood bark (double-shred) | 1-2 years | Natural brown | General ornamental beds | $28-40 |
| Cypress mulch | 2-3 years | Light brown | Tree rings, humid areas | $35-50 |
| Pine bark (nuggets) | 3-4 years | Red-brown | Acid-loving plants, drainage | $40-55 |
| Cedar mulch | 2-3 years | Light tan | Foundation plantings, aromatic | $45-65 |
| Dyed hardwood (black/red/brown) | 1 year color, 2 yr material | Dyed | Decorative front beds | $35-50 |
| Rubber mulch | 10+ years | Various dyed | Playgrounds, dog runs | $200-300 |
| Straw / hay | 1 season | Natural | Vegetable gardens, new seed | $20-30 |
| Leaf mold / compost mulch | 1 year | Dark brown | Vegetable and perennial beds | $30-45 |
Dyed mulches fade to gray in direct sun within 1 year. Rubber mulch does not decompose and doesn't enrich soil but outlasts organic types 5-10×.
Real-World Example Calculations
Foundation Beds 300 ft² @ 3 in cypress
Front-of-house foundation plantings and shrub beds.
- Area
- 300 ft²
- Depth
- 3 in
- Mulch type
- Cypress
Takeaway: Break-even point — bulk delivery at $35/yd³ = $100 vs. 38 bags × $5.50 = $209. Go bulk.
Tree Ring 8 ft diameter × 4 in pine bark
Decorative tree ring around mature oak tree.
- Diameter
- 8 ft
- Depth
- 4 in
- Area
- 50.3 ft²
Takeaway: Small project — bags are fine. Keep mulch 3 in away from trunk to prevent rot.
Full Property 2,500 ft² @ 3 in hardwood
All ornamental beds around a suburban home.
- Area
- 2,500 ft²
- Depth
- 3 in
- Mulch type
- Hardwood bark
Takeaway: 2 truck deliveries. $700-900 bulk vs. $1,600-1,900 bagged. Bulk is mandatory at this scale.
Frequently Asked Questions
How much mulch do I need?
At 3-inch depth: 1 cubic yard per 108 ft², or 1 bag (2 ft³) per 8 ft². For a 400 ft² garden bed at 3 inches: 3.7 cubic yards or 50 bags.
How deep should mulch be?
2 inches for new plantings, 3 inches for established beds, 4 inches for slopes. More than 4 inches suffocates roots and harbors pests. Refresh mulch annually to maintain depth as it decomposes.
How many bags of mulch in a yard?
Standard 2-cubic-foot bags: 13.5 bags per cubic yard. Always round up when ordering bags. Bulk is cheaper for any project needing more than 5-6 bags.
How much does mulch cost?
In 2026: $28-55 per cubic yard bulk delivered. Bagged at stores: $4-7 per 2-ft³ bag (equivalent to $54-94 per yd³). Specialty and dyed mulch runs 25-50% higher. Rubber mulch is $200-300 per yd³.
When is the best time to mulch?
Spring after the soil warms, typically mid-April to mid-May in northern climates, earlier in the south. Too-early mulching traps cold air and delays soil warming. Fall mulching is acceptable for winter insulation of perennials — apply 4-6 inches after first freeze.
Which mulch is best?
Depends on goals. Hardwood bark for general use (decomposes, feeds soil). Pine bark nuggets for acid-lovers and long-lasting beds. Cedar for natural pest deterrence. Rubber for playgrounds. Straw for vegetable gardens.
Does mulch prevent weeds?
Yes — 3-inch mulch blocks 60-80% of weed germination by depriving seeds of light. Combine with a pre-emergent herbicide or landscape fabric for 90%+ weed suppression. Never more than 4 inches — thicker mulch invites different weed problems like nut sedge.