Mulch & Compost Calculator
Calculate how much mulch or compost you need for your garden beds, including cost estimates for bulk and bagged options.
A 10x4-foot garden bed mulched 3 inches deep needs about 10 cubic feet of material, or roughly 0.4 cubic yards. That is 5 standard 2-cubic-foot bags. Bulk delivery is almost always cheaper for areas larger than 100 square feet.
Data last updated: March 2026
Wood Chip Mulch: ~600 lbs per cubic yard, $30/yard bulk
You Need
Calculation Breakdown
Material: Wood Chip Mulch · Depth: 3" · 10' x 4'
Recommended Products
Wood Chip & Bark Mulch
Natural wood chip and shredded bark mulch bags. Suppresses weeds and retains moisture.
Organic Compost & Soil Amendments
Premium organic compost and garden amendments. Enriches soil and feeds beneficial microbes.
Garden Wheelbarrows & Carts
Heavy-duty wheelbarrows and garden carts for moving mulch and compost. Saves your back.
Frequently Asked Questions
For most garden beds, apply 2 to 3 inches of mulch. This depth is enough to suppress weeds and retain moisture without suffocating plant roots. Around trees and shrubs, you can go up to 4 inches. For garden pathways, 4 to 6 inches provides a more durable surface. Avoid piling mulch deeper than 6 inches, as it can prevent water from reaching the soil and create a habitat for rodents.
How This Calculator Works
This calculator computes mulch or compost volume using the formula: length x width x depth. It converts cubic feet to cubic yards (divide by 27) and calculates the number of standard 2-cubic-foot bags needed. Bulk pricing is based on typical landscape supply yard rates, while bagged pricing reflects average retail bag costs. Weight estimates vary by material: compost is the heaviest at around 800 lbs per cubic yard, while straw is the lightest at roughly 400 lbs per cubic yard.
Mulching Tips
- Apply 2 to 3 inches of mulch around vegetables and flowers. Deeper layers (4 to 6 inches) work well for pathways and around trees.
- Keep mulch 2 to 3 inches away from plant stems and tree trunks to prevent rot and pest problems.
- Refresh mulch annually in spring. Most organic mulches break down over one to two growing seasons, adding nutrients back to the soil.
- Consider your goals: wood chips are best for weed suppression, compost adds the most nutrients, and straw is ideal for vegetable gardens because it breaks down quickly.
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