Mulch Calculator for Beds, Rings and Refreshes

Every other material on this site is bought by weight. Mulch is not, and that single difference is where most spring orders go wrong. Shredded hardwood runs about 600 lb a cubic yard, roughly a fifth of what base stone weighs, so the tons line on the result panel is a true figure that nobody orders by. Read the cubic yards instead. This mulch calculator gives you both, plus the bag count for anyone still pricing the job against a garden-center trolley.

Why the tonnage on the result line is not the number to order from

A tenth of a ton sounds like almost nothing, and it is three wheelbarrow loads of mulch. At about 0.30 tons a cubic yard, a four-yard order shows as 1.2 tons on the panel, which reads like a rounding error next to a stone delivery and is in fact a pile the size of a small car. Take the yardage. Bulk mulch is loaded by volume.

Why 3 inches over a bed that already holds 2 doubles your order

A bed that was mulched last spring usually still has most of that layer under a crust. Rake the crust loose, measure what is left, and enter only the difference needed to bring the total to 2 or 3 inches. Enter a full depth over an existing layer and you order roughly twice what the beds can take without smothering roots.

Turning a curved foundation bed into a rectangle you can enter

Beds along a house wander in and out around downspouts, meter boxes and shrubs. Pace the length along the wall, then measure the bed width at three or four points and average them. For an island bed or a tree ring, switch the shape row to circle and measure straight across the widest part for the diameter.

Refreshing 53 feet of foundation bed and one tree ring

An illustrative job, not a customer project. The beds run 53 ft along the front of the house at an average 3 ft deep, which is 159 square feet. A tree ring 8 ft across adds a circle: 4 ft radius, 4 x 4 x 3.14, or about 50.3 square feet. Both are going down at the same depth, so they can be entered together under multiple areas, and the total is roughly 209 square feet.

Last year's mulch is raked loose and holds about an inch, so the refresh depth is 2 inches. Two inches is 2/12 of a foot, so 209 x 2/12 gives 34.8 cubic feet. Divided by 27 that is 1.29 cubic yards. At about 600 lb a yard the load weighs roughly 775 lb, and in bag terms 1.29 x 13.5 comes to 17.4, so 18 two-cubic-foot bags. Rounding that yardage up to 1.5 gives enough to finish the ring properly and top the strip by the steps that always wears thin first.

What each control does with your bed measurements

Rectangle takes length and width in feet and suits a border or a strip along a fence. Circle takes a diameter in feet for rings and island beds. Multiple areas holds up to five entries, which is what the whole-yard total above is built from.

Depth (inches) runs from 0.25 to 24, so a light half-inch dressing is as valid an entry as a new bed at 3 inches. One figure covers every area in a run, so beds wanting different depths are separate runs added together. The material select sets the weight used for the tons line. The tick box adds 5 per cent for compaction and spillage and is entirely optional; on mulch it is worth ticking for a large order, since shredded material blows and scatters off a wheelbarrow far more than stone does.

The results come back as cubic yards, tons and cubic feet, with Email my quote to send them to yourself.

Cubic yards, cubic feet and the bag arithmetic

A cubic yard is 27 cubic feet, however it is filled. That is why a yard equals 13.5 of the two-cubic-foot bags sold at garden centers, or 9 of the three-cubic-foot size: divide 27 by the figure printed on the bag. The cubic feet output is the one to read if you are comparing against bags at all, and the yardage is what a bulk order is placed in.

Coverage follows the same arithmetic. One cubic yard spread an inch deep covers 324 square feet, at 2 inches it covers 162, at 3 inches 108, and at 4 inches 81.

Depth by bed, and the clearances Virginia summers make matter

Three inches over bare soil suppresses weed germination and holds moisture through a humid July. Two inches is a refresh over a loosened existing layer. Beyond 4 inches the layer starts working against the plants, because a thick wet mat limits the air reaching roots, and thunderstorm rain sits in it.

Keep the mulch pulled back 3 to 6 inches from every trunk and shaped as a flat ring rather than a cone. Bark that stays covered can rot, and rodents will use the cover. Along the house, keep it 6 inches clear of the siding and below the slab line, at 2 to 3 inches deep.

Playground surfacing is a different specification: use a playground-certified chip rather than landscape shred, at 6 inches or more, and source that locally rather than adding it to this order. An 18 ft by 12 ft play area at 6 inches is 216 square feet at half a foot, or 108 cubic feet, which is exactly 4 cubic yards.

Which mulch, and what it changes

The calculator is set for Shredded Mulch, the hardwood shred that mats together and holds its place on a mild slope, which is the reason it is the usual choice on Piedmont beds that shed thunderstorm runoff. Chip and nugget forms sit longer before breaking down but float and travel in heavy rain, and dyed material keeps its color further into the season. None of that changes the volume: every form is calculated the same way, so the type affects how the bed looks and how often you are back out there, not how much you order.

When the yardage is settled, pick your quantity and date on the product page, where delivery is arranged by ZIP: the order is matched to a supplier in the network near that address, and an agent confirms the exact delivery address before the load goes out. A load spread within a week or two beats one left heaped in the drive, since a deep pile left standing a month can sour in the middle.

If the bed needs filling rather than covering, size the bed soil before the mulch goes on first, and take screened topsoil for the lawn edges on the same order where the grass has crept back. For a bed that washes out every August, a stone mulch instead holds where bark does not, and you can size a river rock bed the same way; pea gravel for a path through the beds is the usual companion. Everything else is in the bulk catalogue.

Common questions

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