XCalculator
Calculators that show the math
Every tool puts the formula, a worked example and sources on the same page — so you can check the number, not just trust it.
- No account
- No pop-ups
- Results in the HTML
Home & Garden
Order the right volume of soil, mulch, gravel or concrete before the truck arrives.
- Cubic Yard Calculator For mixed materials when suppliers quote by the cubic yard
- Topsoil Calculator Lawns, raised beds and reseeding — not structural fill
- Dirt Calculator Fill dirt for grading, holes and raising grade
- Rock Calculator Landscape rock and gravel sold by the ton
- Mulch Calculator Bark and wood mulch for beds — light volume, bag or bulk
- Gravel Calculator Driveways, paths and pads that need compacted stone
- Concrete Calculator Slabs, shed pads and footings — order by the yard
- Pool Salt Calculator Saltwater pools — raise ppm without overshooting the cell
Health
Simple planning estimates with clear assumptions — not medical advice.
Finance
Coast FIRE math you can audit: nest egg, growth years and the gap to cover.
Military
Current Army waist-to-height standard, plus the legacy height-weight table for reference.
AP Exams
Practice score estimates from College Board section weights — curves are unofficial.