User Rating 0.0 ★★★★★

Total Usage 0 times

Category Gardening

1. Add Garden Beds

Bed Shape

Mulch Depth (Inches)

Shape	Dimensions	Volume (ft³)	Action
No beds added yet.

2. Product & Calculate

Bag Size

Price per Bag / Bulk Yard

Is this tool helpful?

Your feedback helps us improve.

★ ★ ★ ★ ★

About

Precise material estimation distinguishes a professional landscape project from a weekend struggle. Applying mulch requires specific depth management to suppress weeds without suffocating root systems. A layer that is too thin fails to retain soil moisture. A layer that is too thick creates a barrier that prevents water from reaching the soil and may encourage fungal growth.

Homeowners often misjudge the volume needed for irregular garden beds. This tool solves the geometry problem by decomposing complex landscapes into standard shapes. You can combine multiple beds into a single project total. This ensures you purchase the exact number of bags or cubic yards required for the job. Accurate calculation prevents the frustration of returning to the store for a few missing bags or dealing with a pile of excess material in the driveway.

Formulas

The total volume V_total is the sum of individual bed volumes. All inputs are normalized to feet before calculation.

Rectangular Bed:

V = L × W × d_inch12

Circular Bed:

V = π × r² × d_inch12

Triangular Bed:

V = 0.5 × b × h × d_inch12

Bag Estimation:

Bags = ceil(V_totalVol_bag)

Reference Data

Mulch Depth	Coverage (1 Cu. Yard)	Coverage (2 Cu. Ft. Bag)	Coverage (3 Cu. Ft. Bag)
1 inch	324 ft²	24 ft²	36 ft²
2 inches	162 ft²	12 ft²	18 ft²
3 inches	108 ft²	8 ft²	12 ft²
4 inches	81 ft²	6 ft²	9 ft²
5 inches	64.8 ft²	4.8 ft²	7.2 ft²
6 inches	54 ft²	4 ft²	6 ft²

Frequently Asked Questions

Most professional landscapers recommend a depth between 2 and 3 inches. This thickness is sufficient to suppress weed germination and retain soil moisture. Exceeding 4 inches can limit oxygen exchange to the roots and may cause the bark to mat down.

Break the irregular shape into smaller standard geometric figures. For example, a kidney bean shape can often be approximated by two overlapping circles or a rectangle with rounded ends. Calculate the volume for each section separately and sum them up.

Bulk is generally cheaper for projects requiring more than 2 cubic yards (approx. 27 bags). However, bulk delivery fees can offset the savings. For smaller projects under 1 cubic yard, bags are easier to transport and handle without specialized equipment.

The calculation relies on volume, not weight. Therefore, density does not change the cubic footage required. However, some mulch types like pine straw settle more significantly than hardwood bark, so you might order 10% extra for light materials.