Even Spacing Calculator
Exact on-center spacing for posts, balusters, shelving, and pickets — calculated instantly
Download Free on Google Play
Exact on-center spacing for posts, balusters, shelving, and pickets — calculated instantly
Download Free on Google PlayThe Even Spacing Calculator is the ultimate tool for woodworkers, DIY enthusiasts, and construction professionals who need perfectly distributed layouts in seconds. Whether you're installing railing balusters, fence pickets, deck planks, bookshelves, or wall art, this app handles the complex math so you can focus on building.
If you want to do it by hand, here's the whole thing. To space n pieces evenly across a length L, where each piece is w wide and a piece sits at each end of the run:
That gives you the distance from the center of one piece to the center of the next. The clear gap between pieces is simply:
The reason you measure on-center rather than gap-to-gap: mark every center from one end with a tape, and a rounding error can't accumulate. Measure each gap in turn and the errors stack — by the seventh picket you're visibly out.
A deck rail with 96" between posts, 8 balusters, each 1.5" wide:
A fence panel 2000 mm wide, 6 pickets, each 50 mm wide:
Real numbers rarely land that clean. Divide 2400 mm by 7 and you get 342.857… — and that's the point where the scrap paper starts. The app does this division for you, rounds every position to something you can actually mark (a whole millimetre, or a fraction down to 1/64"), and lists every center from one end so nothing drifts. It also handles edge offsets when the run doesn't start flush, and shows the layout as a diagram before you cut.
Customize accuracy up to 1/64" for meticulous detail work. Perfect for fine woodworking where every fraction matters.
Now supports both Imperial (inches) and Metric (mm) measurements. Work in whatever system you prefer.
Get the exact center-point for every piece, ensuring perfect alignment for posts, balusters, and more.
Toggleable view that lists the "start" and "center" positions for every single piece—perfect for long runs like fences or decks.
NEW: Set inset spacing from edges for professional-looking layouts with proper margins.
NEW: Calculate exact spacing including the width or thickness of your materials for gap-accurate layouts.
Save and share your measurements with your team or for future reference. No more losing your calculations.
A diagram draws your spacing as you type, so you can see the run before you cut anything. Catch the mistake on the screen instead of on the lumber.
Every calculation is saved. Come back to the job tomorrow, or hit the next identical run, and pull the numbers straight back up — no re-entering.
No subscriptions, no paywalls, no unlocks — the whole app, no limits. It's supported by a single banner ad at the bottom of the screen. That's the deal.
Balusters, spindles, shelving, shelf brackets, cabinet hardware, and trim work. Get professional results every time.
Timber screws, fasteners and joists at equal centers. Work out your fixing pattern in millimetres or inches before the first screw goes in.
Fence posts, fence pickets, deck boards, siding, framing studs, and structural layouts. Build with confidence.
Picture frames, wall hooks, gallery walls, floating shelves, and lighting fixtures. Achieve that designer look.
Deck railings, fence pickets, pergola beams, and garden borders. Perfect outdoor spacing in any weather.
Drawer pulls, shelf pins, table legs, and decorative details. Precision for custom furniture.
Any task where "eyeballing it" just isn't good enough. Stop guessing, start measuring.
Using the Even Spacing Calculator is simple:
View the detailed table to see start and center measurements for every single piece. Export your layout to reference while working, or share it with your crew.
Like all ProDirt apps, Even Spacing Calculator follows our core principles:
Stop calculating and start creating.
Download Even Spacing Calculator Free