Mulch Calculator
Getting the right amount of mulch for your landscaping project prevents wasted trips and leftover material. Our mulch calculator converts your bed dimensions and desired depth into cubic yards for bulk delivery or number of bags for smaller projects. Whether you're refreshing existing beds or starting new landscaping, accurate calculations save money and time. Simply enter your bed area and how deep you want the mulch, and we'll tell you exactly what to order.
- Free forever
- Formula-sourced
- Updated 2026-02-04
- No sign-up
2" to refresh, 3-4" for new beds
Bulk mulch typically $30-60/cu yd or $40-80/m³
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Fill in the form to see your estimate.
How It's Calculated
1. Area = Length × Width 2. Volume (cu ft) = Area × (Depth ÷ 12) 3. Cubic Yards = Volume ÷ 27 4. Total Needed = Cubic Yards × (1 + Waste Factor) 5. 2 Cu Ft Bags = Total Volume (with waste) ÷ 2 (rounded up) 6. 3 Cu Ft Bags = Total Volume (with waste) ÷ 3 (rounded up) 7. Cost = Total Cubic Yards × Price per Cubic Yard 8. Mulch Weight = Cubic Yards × 500 lbs/cu yd (raw volume) Price entered as $/m³ is converted to $/cu yd internally (1 m³ ≈ 1.308 cu yd). Coverage per cubic yard: • 1" deep = 324 sq ft • 2" deep = 162 sq ft • 3" deep = 108 sq ft • 4" deep = 81 sq ft
Worked Examples
A 30×6 foot bed at 3" deep: Volume = 180 × 0.25 = 45 cu ft = 1.67 cu yd. With 5% waste = 1.75 cu yd. Cost ~$79. Or buy 24 bags (2 cu ft each).
A 40×8 foot area at 2" (refresh depth): Volume = 320 × 0.167 = 53.4 cu ft = 2 cu yd. With waste = 2.1 cu yd. Cost ~$95. Bulk delivery becomes cost-effective at this volume.
A 1,000 sq ft area at 4" deep: Volume = 333 cu ft = 12.3 cu yd. With waste = 13 cu yd. Cost ~$585 for mulch, plus $75-100 delivery. Much cheaper than 175+ bags!
Assumptions & Waste Factor
- Standard mulch depth is 2-4 inches
- One cubic yard covers 324 sq ft at 1" deep
- One cubic yard covers 108 sq ft at 3" deep
- Standard bag is 2 cubic feet (3 cu ft bags also common)
- 13.5 bags (2 cu ft) or 9 bags (3 cu ft) per cubic yard
- Mulch density of ≈500 lbs/cu yd (typical shredded hardwood — bark mulch is lighter, compost-blends heavier)
- Bulk prices don't include delivery (typically $50-100)
Mulch waste is typically low (5%) since it's spread by hand. Add 10% for irregular beds with many plants to work around. Bulk delivery is more economical for orders over 2 cubic yards.
Frequently Asked Questions
How deep should mulch be?
Apply 2-4 inches of mulch. Use 2 inches for fine mulches or annual refreshing, 3-4 inches for new beds or coarse mulches. Never pile mulch against plant stems or tree trunks. Keep it a few inches away.
How much area does a cubic yard of mulch cover?
One cubic yard covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, or 81 sq ft at 4 inches deep. The deeper you spread it, the less area each yard covers.
Should I buy bagged or bulk mulch?
Bulk mulch is more economical for areas over 100-150 square feet. Bagged mulch is convenient for small projects or when you can't receive bulk delivery. Bulk also reduces plastic waste.
How many bags of mulch in a cubic yard?
A cubic yard equals 27 cubic feet. Standard 2 cu ft bags: 13.5 bags per cubic yard. Standard 3 cu ft bags: 9 bags per cubic yard. Always cheaper to buy bulk for large projects.
What type of mulch is best?
Hardwood mulch lasts longest and enriches soil as it decomposes. Pine bark is acidic, good for azaleas and rhododendrons. Cypress is durable but not sustainable. Rubber mulch lasts forever but doesn't improve soil.
How often should I replace mulch?
Most organic mulches should be refreshed annually with 1-2 inches. Completely replace mulch every 2-3 years. Remove old mulch if it's matted, moldy, or has become too thick (over 4 inches).
Does mulch attract termites?
Mulch doesn't attract termites, but it provides moisture and cover they like. Keep mulch 12 inches from your foundation and use inorganic mulch (gravel, rubber) directly against buildings in termite-prone areas.
When is the best time to apply mulch?
Apply mulch in late spring after soil warms, or in fall to protect roots. Avoid mulching too early in spring because it keeps soil cold and delays plant growth. Fall mulch protects plants from winter temperature swings.
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Disclaimer: This calculator provides estimates for planning purposes only. Actual material requirements may vary based on site conditions, installation methods, and other factors. Always consult with a qualified professional before making purchasing decisions.