Spacing Calculator
Three spacing problems, one tool: studs and joists on-center (count plus the last bay), balusters and pickets at uniform gaps under your maximum, and fence or deck posts to a max span with the even spacing that results.
Planning tool — results are estimates for quoting and ordering, not engineering or building-code advice.
Common questions
How many studs in a wall?
Run length divided by the on-center spacing, rounded up, plus one to close the run — that's the base count this tool gives you. Add doubles at ends, corners, and openings to suit how you frame.
How does the baluster mode avoid a skinny last gap?
Instead of marching at a fixed spacing and leaving a remainder, it computes the fewest balusters that keep every gap under your maximum, then distributes the gaps evenly — every gap identical.
What max gap should I use for balusters?
The tool defaults to 4", a common guard standard, but it's just a default — set it to whatever your local code requires.
Related: Stairkey for general contracting · Stair calculator
More free calculators
All 14 are free, feet-and-inches in, no sign-up. Pick the next one for the job.
Concrete & site work
Finishes & materials
Layout & geometry
This solves one measurement. The Takeoff Builder prices the whole job.
Walk the rooms, enter dimensions, and formula-driven scope turns measurements into quantities, prices, and the estimate itself — from $20/mo, capped, no surprise bills.