How many sandbags do I need?
Measure the length of wall you need and how high it has to be. The calculator builds it the way flood crews do — a staggered pyramid, three times as wide at the base as it is tall — and tells you how many bags to order.
Rules of thumb
- Front door: about 27 bags (a standard 3 ft doorway, 12 in high)
- Garage door: about 115 bags (a 16 ft two-car garage, 12 in high)
- Driveway diversion: about 132 bags (a 30 ft diversion wall, 8 in high)
- Yard perimeter: about 704 bags (100 ft of wall, 12 in high)
Start from a common job
Along the ground, in feet
Finished height, in inches
You'll need about
3 layers, 4 bags wide at the base (36 in), 13 along the length — includes 10% extra for ends and corners.
How the calculator works
A sandbag wall that holds is built like brickwork: each row is offset by half a bag so the joints never line up, and anything more than about a foot tall is built as a pyramid with a base roughly three times its height. The calculator models exactly that shape, using the size of a standard filled, tamped sandbag:
- Each bag covers about 15 inches of wall length once overlapped with its neighbor.
- Each bag is about 10 inches wide across the wall.
- Each layer adds about 4 inches of height after tamping.
- We add 10% for the ends of the wall, corners and tie-ins.
Real walls vary with how full the bags are and how hard they're tamped, so treat the result as a solid starting point and round up if you're protecting something important. For step-by-step instructions, see how to stack sandbags.
Diverting water vs. holding it back
Most homes don't need a tall wall — they need a low one in the right place. A wall a foot high that steers runoff around a garage or door and toward the street does more good than a tall one trying to hold back standing water. If you live below a burned hillside, read our guide to burn-scar debris flows before you build.
Rain in the forecast? Don’t wait for it.
When a big storm is on the way, sandbags sell out across LA. Get yours delivered now and store them in the garage until you need them.