Mulch Calculator
Calculate how many cubic yards or bags of mulch you need for your landscaping project.
How It Works
This calculator converts your bed area and desired mulch depth into cubic yards and bag counts.
Formula: Cubic Yards = (Area in sq ft × Depth in inches) / 324. The number 324 comes from 12 inches per foot × 27 cubic feet per cubic yard.
Bag counts are rounded up since you cannot buy partial bags. Weight estimates vary by mulch type — hardwood mulch weighs about 800 lbs per cubic yard while cedar weighs closer to 500 lbs.
Cost estimates assume bulk delivery at $30-$50 per cubic yard, which is the most common pricing range for residential deliveries.
Frequently Asked Questions
How much mulch do I need?
Measure your bed area in square feet (length x width) and decide on a depth. Most landscaping uses 2-3 inches of mulch. Then use the formula: cubic yards = (square feet x depth in inches) / 324. This calculator handles that math for you and converts to bags.
How deep should mulch be?
For most landscape beds, 2-3 inches is ideal. Around trees, keep mulch 3-6 inches away from the trunk to prevent rot. Avoid piling mulch deeper than 4 inches, as it can prevent water from reaching plant roots and create a habitat for pests.
Should I use bags or bulk mulch?
For small beds under 100 sq ft, bags are convenient. For larger areas, bulk delivery (sold by the cubic yard) is significantly cheaper — typically $30-$50 per cubic yard delivered vs $4-$7 per 2 cu ft bag ($54-$94 per cubic yard equivalent). Bulk also reduces plastic waste.
How often should I replace mulch?
Organic mulch breaks down over time. Hardwood and dyed mulch last about 1-2 years. Pine bark and cedar can last 2-3 years. Top up annually with 1-2 inches rather than fully replacing. Remove old mulch only if it has become compacted or matted.
What is the best type of mulch for flower beds?
Shredded hardwood is the most popular choice — it stays in place, breaks down slowly, and enriches soil. Cedar mulch adds insect-repelling properties. Pine bark is good for acid-loving plants like azaleas and blueberries. Dyed mulch holds its color longer but offers fewer soil benefits.