Why We Built This Window Well Gravel Calculator
Most online gravel calculators are built for flat driveways or garden beds and only output raw cubic yards. That doesn't help a homeowner standing at Home Depot, Lowe's, or Menards trying to figure out how many 50-lb bags of pea gravel to load into their vehicle.
Furthermore, nearly 90% of residential basement window wells are curved semi-circles (semi-ellipses). Using a rectangular formula on a curved window well causes homeowners to overbuy stone by 25% to 35%. We built WindowWellGravel.online to provide exact bag counts, filter fabric cut sizes, and window sill clearance checks in seconds.
How Our Engineering Formulas Work
Area = (π × (Width ÷ 2) × Projection) ÷ 2
Accurately models curved galvanized steel and plastic basement window wells.
- Washed Pea Gravel (3/8"–1/2"): 96 lbs / cu ft
- #57 Crushed Stone (3/4"): 100 lbs / cu ft
- Washed River Rock (1"–2"): 92 lbs / cu ft
Editorial & Building Code Standards
All drainage depth guides, filter fabric sizing, and window sill clearance checks on our platform follow industry waterproofing practices and International Residential Code (IRC Section R310) emergency egress guidelines.