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Mulch Calculator
Enter bed dimensions, mulch depth, and bag size to estimate volume in cubic feet and yards, bags to buy, and cost. Dimensions accept feet or metres; volume stays in cubic feet and yards, the way mulch is sold. An estimate — beds are rarely perfect rectangles.
Last updated: September 30, 2026
Your result · Bags to buy
15
Rounded up to whole bags.
- Volume
- 30cu ft
- Volume
- 1.11cu yd
- Estimated cost
- $60.00
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What your result means
Bags to buy is the headline: whole bags covering your bed at the chosen depth. Volume in cubic feet and yards lets you compare against bulk delivery pricing.
If bags look high, double-check depth — one inch over a big bed is many bags.
How the calculation works
- Convert bed dimensions to feet and multiply by depth for cubic feet, dividing by 27 for cubic yards.
- Divide cubic feet by bag volume and round up to whole bags.
- Multiply bags by price per bag for the cost.
Formula
Formula
volume = length × width × depth; bags = round up (volume ÷ bag volume); cost = bags × price
- Volumelength × width × depth (converted to feet)
- Cubic yardscubic feet ÷ 27
- Bagsround up (cubic feet ÷ bag volume)
- Costbags × price per bag
Worked examples
Example: 10×12 ft bed at 3 in, 2 cu ft bags at $4
- dimUnit: ftlength: 10width: 12depthUnit: indepth: 3bagVolume: 2pricePerBag: 4
Result: Volume 30 · Volume 1.11 · Bags to buy 15 · Estimated cost $60.00
Example: 5×2 m bed at 8 cm, 2 cu ft bags
- dimUnit: mlength: 5width: 2depthUnit: cmdepth: 8bagVolume: 2pricePerBag: 4
Result: Volume 28.3 · Volume 1.05 · Bags to buy 15 · Estimated cost $60.00
Assumptions
What this calculation takes for granted — check these before relying on the result.
Assumptions:
Limitations
Why your real figure may differ:
Frequently asked questions
How deep should mulch be?
2–4 inches settled is the standard target: enough to suppress weeds and hold moisture, shallow enough to let water through. Keep it a few inches from stems and trunks.
Bags or bulk delivery?
Bags win for small beds and exact counts; bulk by the cubic yard is usually far cheaper past 2–3 yards. This calculator’s cubic-yard figure is exactly what bulk yards quote against.
Why round bags up?
Bags sell whole, beds are irregular, and spillage happens. The rounded figure also covers the settling that follows fresh spreading.
Does mulch type change the math?
Only the settling rate and price — volume math is identical. Shredded bark knits and stays; nuggets migrate; all decompose and need topping up.