Mulch Redistribution Calculator

Measure a thick spot and a thin spot. Plan the move, then remeasure the thin spot before deciding whether to buy more.

Move first. Buy only after checking.

in-place cubic feet

Donor layer to lift—

Receiver needs before moving—

Planned difference—

Enter both measured areas and depths to see a planning balance.

A Thick area to thin

Measure the top layer you intend to move, leaving the depth you choose.

Length ft Width ft Current depth in Depth to leave in

B Thin area to fill

Measure the receiving area. Do not assume all lifted material will be usable.

Length ft Width ft Current depth in Target depth in

After moving: check before buying

Material may be discarded, settle or spread differently. Measure the receiving depth again.

Receiving depth after moving in Your bag's printed volume cu ft

Still needed — cu ft

New whole bags —

Two readings, not one guess

Two-stage worksheet: measure material to lift from a thick area and need in a thin area, move suitable material, then remeasure the thin area before buying

The first result is only a geometric comparison of two in-place layers. Area is length × width; layer volume is area × positive depth difference ÷ 12. After moving material, the remeasured receiving shortage is area × positive difference between your target and new measured depth ÷ 12. Only then is the shortage divided by a bag volume you entered and rounded up to whole bags. One cubic yard is 27 cubic feet.

Iowa State University Extension's garden-bed method supports the area, converted-depth, bag and cubic-yard arithmetic. University of Maryland Extension's excess-mulch guidance explains why accumulated material should be checked rather than covered with more; it says old mulch may be worked into a planting bed or moved to other garden areas. Virginia Cooperative Extension says an overly deep layer at a tree's root flare should be raked out to reduce depth and spread evenly. That site-specific correction is not a general reuse guarantee. Check the actual material and receiving plants before moving it.

Illustrative worksheet, not a recommended depth: a 10 × 4 ft thick area at 4 in, left at 2 in, has 6.67 cu ft to lift. A 12 × 4 ft receiving area at 1 in, targeted at 2.5 in, initially needs 6 cu ft. The geometry suggests 0.67 cu ft extra. If the receiving area actually measures 2 in after moving, it still needs 2 cu ft: at an example entered 2-cu-ft bag size, that is one whole new bag. The second measurement, not the optimistic planning surplus, controls the purchase count.

What this worksheet cannot decide

It does not tell you whether old mulch is suitable to reuse, whether two materials should be mixed, or how loose material will pack after lifting. It does not calculate truck capacity, weight, disposal rules or a supplier's price. Keep mulch away from trunks and plant crowns according to the needs of the site; do not treat the example depths as prescriptions.

If unsuitable material needs to be removed, use the mulch removal cost worksheet. If there is no donor area, use the existing-depth and top-up calculator.

Questions before you move mulch

Can I move existing mulch to another bed?

Sometimes. University of Maryland Extension says old mulch may be gently worked into a planting bed or removed and worked into other garden areas. Check the material, its condition, the receiving plants, and the current depth first; this calculator cannot decide whether a batch is suitable to reuse.

Can I estimate the bags from the pre-move balance?

Do not use the pre-move difference as a bag count. Move only material you judge suitable, measure the receiving depth again, and enter that measurement, target depth, area, and the bag volume printed on the package. The calculator rounds the remaining measured volume up to whole bags.