Outdoor blow mold driveway count
Estimate how many classic blow-mold figures fit along a driveway edge from run length and spacing for Prince William County Christmas lawns.
molds = floor(run_ft × 12 ÷ spacing_in) + 1
When to use
Use this for plastic blow-mold Santas, carolers, and snowfolks lining a driveway — not inflatable spacing and not lighted deer herd layout.
Keep molds back from plow/shovel edges (often 18+ in) and leave sightlines at the apron. Includes end stations (+1).
Usable decorate length along one edge.
Center-to-center; taller molds need more air.
1 = one side; 2 = both driveway edges.
Bulb failures and symmetry fixes.
Worked example
Example defaults — Run 40 ft; Spacing 48 in; Sides 1; Spare 1.
Compute: per edge = floor(40 × 12 ÷ 48) + 1 = 11; total 11; buy 12 with spare.
Stagger heights (caroler, Santa, snowman) so the line does not read as identical clones from the street.
Second example: one input changed
From the defaults (Driveway edge run (feet) = 40; Center spacing (inches) = 48; Edges to decorate = 1; Spare molds = 1), the calculator shows:
Molds per edge: 11
Total molds: 11
Buy with spares: 12
Now raise Driveway edge run (feet) from 40 to 60 and keep the other entries. The result becomes:
Molds per edge: 16
Total molds: 16
Buy with spares: 17
Comparing the two runs tells you how sensitive the answer is to that one measurement. If a small change in it swings the result a lot, measure it twice.
Limits / assumptions
Units: feet and inches.
Assumptions: single file per edge; molds similar footprint; no gate cutouts modeled.
Not a substitute: HOA rules, underground utility locate, or cord amp budgets.
Keep figures clear of vehicle mirrors and sidewalks. Stake bases; cord covers across walkways.
FAQ
Both sides different lengths?
Run the tool twice and add the counts.
Mixed with inflatables?
Give inflatables their own clear zone — do not share tight spacing.
Power?
Once you know the mold count, sum the nameplate watts and check them against your circuit headroom.