How to choose a calculator
Match the shape of the job, not just the material name. Slabs and pads use rectangular volume; post holes and Sonotubes use cylinders; mulch beds use area × depth; fence and deck tools count pieces. Each page shows the formula, a worked example, waste or compaction caveats, and cited sources. Prefer the dedicated tool over forcing one calculator to do another’s job.
| If you are estimating… | Open | Related guide |
|---|---|---|
| Patio / pad concrete | Concrete calculator | 10×10 slab |
| Fence post concrete | Post holes | Fence post bags |
| Mulch or gravel volume | Mulch / Gravel | Mulch depth |
| Fence / deck / roof / paint | Outdoor structures hub | 12×16 deck list |
| Seed or fertilizer | Lawn hub | Seed rates |
Waste factors (often 5–10%), rock density, and bag yields vary by product and region. Treat every result as a planning estimate and confirm labels, supplier tickets, and local code before you buy. Full formula notes live on each tool page and in methodology.