How the mulch planner works
Most gardens are not one neat rectangle. A front bed, a ring around a tree and a long curved border along the lawn all need mulch, often from the same order. This planner lets you add each of them as its own shape, takes out anything you are not covering, and turns the total into bags or a bulk amount you can buy in one trip.
How to measure several beds
- Sketch your beds on paper and give each one a name, such as “Front bed” or “Maple ring”.
- Break odd shapes into simple ones. A kidney-shaped bed is usually close to a rectangle plus a half circle. Measure the length and width of straight beds, and the diameter (the full width across) of round ones.
- Measure curved borders along the curve with a tape or a garden hose laid on the edge, then take the width in three or four places and use the average.
- Subtract what stays bare, such as stepping stones, a tree trunk, a birdbath base or a small patio inside a bed.
- Note the mulch already there. Push a ruler down to the soil in a few places. The planner orders only the difference between your target depth and what you already have.
Worked example
Here is a small front yard with four areas, a 3 in target depth, no existing mulch and the default 5% allowance. You can load it into the planner with the “Try the worked example” button.
| Area | Shape and size | Area |
|---|---|---|
| Front bed | Rectangle, 20 × 4 ft | 80.00 ft² |
| Tree ring | Circle, 6 ft across | 28.27 ft² |
| Side border | Curved, 30 ft long, 3 ft average width | 90.00 ft² |
| Birdbath base | Circle, 2 ft across, subtracted | − 3.14 ft² |
| Net area | 195.13 ft² |
At 3 in (0.25 ft) deep, the beds hold 195.13 × 0.25 = 48.78 ft³ of mulch. Adding 5% for waste and settling gives an order volume of 51.22 ft³, which is 1.90 cubic yards. With 2 ft³ bags that is 51.22 ÷ 2 = 25.6, rounded up to 26 bags. If your supplier sells bulk in half-yard steps, the bulk order is 2.0 yd³.
Bags or bulk?
Bagged mulch is easy to carry, store and spread a little at a time, and you can return or reuse unopened bags. It usually costs more per cubic yard. Bulk mulch is sold by volume, often in half-yard or quarter-meter steps, and is usually cheaper per yard but may come with a delivery fee and needs a place to unload. If you enter prices from your supplier, the planner compares both options for your exact order, including the delivery fee. It does not know local prices and never looks them up.
Important assumptions
- Depth is the finished depth you want. Each bed can have its own depth; otherwise the target depth is used.
- Existing mulch is subtracted from the depth of every bed, never below zero.
- Waste and settling (default 5%) covers spills, uneven ground and mulch that packs down after watering. Fresh, fluffy mulch can settle more, so raise it if your product suggests that.
- Bag size must match the label. Bags are sold by volume, so a “2 cu ft” bag is used as 2 ft³.
- Rounding: bags are rounded up to whole bags and bulk is rounded up to your supplier’s step.
What this tool does not calculate
- Landscape fabric, edging, soil amendments or weed control.
- Which mulch type, color or depth is right for your plants or climate.
- Live prices, store stock or delivery availability.
- Slopes. Measure sloped beds along the ground, and expect the result to be approximate.
Mulch planner FAQ
What depth should I enter?
The planner starts at 3 inches (75 mm) because it is a common figure for refreshing beds, but it is only a starting value. The right depth depends on your plants, the type of mulch and advice for your area, so enter the depth you plan to use. You can also give individual beds their own depth.
How do I measure a bed with an odd shape?
Split it into simple shapes and add each one as a separate bed: a rectangle for the straight part, a half circle for a rounded end, a curved border for a long sweeping edge. If you already know the area from a plan, choose Known area and type it in.
Why is the order bigger than the volume of my beds?
Two reasons. The waste and settling allowance adds a percentage for spills, uneven ground and mulch that settles after rain or watering. Then bags and bulk are always rounded up to whole bags and to your supplier's bulk step, because you cannot buy part of a bag.
How many bags of mulch make a cubic yard?
A cubic yard is 27 cubic feet. That is 13.5 bags of 2 cubic feet (so 14 when rounded up), 9 bags of 3 cubic feet, or 18 bags of 1.5 cubic feet. In metric, one cubic meter is 1,000 liters, or 20 bags of 50 liters.
Related planners
Mulch quantities are estimates. Mulch products differ in how much they settle and how they are measured, so check the bag label or ask your supplier how their bulk volume is measured before ordering. See how we calculate for the full method.