Mulch Calculator
Turn a garden bed's length, width, and depth into cubic yards of mulch and the number of 2- or 3-cubic-foot bags — with a cost estimate — so you can compare buying bagged versus bulk and order the right amount.
How to Use
- Enter the bed length and width in feet to set the area you are mulching.
- Enter the depth in inches — 2–3" refreshes most beds, 4" suppresses weeds.
- Choose your bag size, 2 ft³ or 3 ft³, to match what the store sells.
- Enter the price per bag for a cost estimate.
- Read the cubic yards, bag count, and total cost, and check the Show Work below.
Show Work
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About the Mulch Calculator
The Mulch Calculator is a simple, free helper for building, materials estimation and site work that runs entirely on your own device. Turn a garden bed's length, width, and depth into cubic yards of mulch and the number of 2- or 3-cubic-foot bags — with a cost estimate — so you can compare buying bagged versus bulk and order the right amount.
How it works
Enter your figures and the result appears instantly, updating the moment you change anything. There is no submit button and nothing to wait for, so it is easy to try a few what-if numbers and compare the results. Just check each box holds the kind of value it expects.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How deep should mulch be?
For most ornamental beds, 2 to 3 inches is the sweet spot — enough to hold moisture and block light without smothering roots. Go up to about 4 inches where you are fighting weeds or covering bare soil. Avoid piling it deeper or against stems and trunks, which traps moisture and invites rot.
How many bags are in a cubic yard?
One cubic yard is 27 cubic feet, so it takes about 13–14 bags of 2 ft³ mulch or 9 bags of 3 ft³ to make a yard. That math is why bulk delivery gets cheaper fast on bigger jobs — once you are buying more than about three yards' worth of bags, bulk usually wins.
Is bagged or bulk mulch cheaper?
Bagged is convenient and fine for small beds, but bulk mulch by the cubic yard is roughly 40% cheaper once you need more than about 3 cubic yards, even after a delivery fee. Use this calculator's yardage to decide: if the job is several yards, price a bulk load against the bag count.
How often do I need to replace mulch?
Organic mulches like bark and wood chips break down and thin out over a season, so most gardeners top them off once a year — usually in spring — adding an inch or two rather than a full re-mulch. Rake and fluff the old layer first so you are not just stacking depth that sheds water.
Should I lay landscape fabric under mulch?
Fabric or a few sheets of newspaper under mulch helps in tree rings and weed-prone borders, but in planted beds it can block the soil benefits of decomposing mulch and clog over time. For active garden beds, a thick enough mulch layer usually controls weeds on its own without fabric.
How do I use the Mulch Calculator?
Just type your numbers. The answer shows up right away — there is no button to press. Change anything and it updates by itself.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
Mulching garden beds
Convert bed dimensions into bags or cubic yards so you buy the right amount for a spring refresh.
Deciding bagged vs bulk
Use the yardage to see when a bulk delivery beats hauling bags from the store.
Edging foundation borders
Size a long narrow border at the depth that keeps it tidy and weed-free.
Building weed-suppressing tree rings
Calculate a deeper 4-inch layer for tree rings and problem weed areas.
Budgeting a landscape job
Get bag count and total cost up front to price mulch across a whole property.
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