Deck & Fence Material Calculator for Illinois Homeowners
Estimate deck boards, framing, fence panels or pickets, posts, and post-hole concrete for a straightforward deck or fence run — plus Illinois digging-safety and permit reminders.
Deck & Fence Material Calculator
Estimate board, joist, post, and concrete quantities for a straightforward deck or fence run.
Actual (not nominal) width of decking board.
Length boards are sold in (e.g. 12, 16, 20 ft).
Estimate only — not a structural design.
These figures are material-quantity estimates, not an engineered plan. Before digging any post holes, call JULIE / 811 to have underground utility lines located. Verify your property lines and any easements, and confirm local frost-depth footing minimums, guardrail and stair requirements, and building/zoning permit requirements with your local authority before starting work.
This tool provides a planning estimate only. Always verify field measurements, product packaging and supplier yields, manufacturer instructions, and local code and permit requirements before purchasing materials or beginning work. This calculator does not collect or save any personal information — nothing you enter here is stored.
How this is calculated
- Deck boards: rows across the width = width ÷ (board face width + gap); board linear feet = rows × length, increased by waste, then divided by stock board length and rounded up.
- Deck framing: joists = (length ÷ joist spacing) + 1, rounded up; joist linear feet = joists × width.
- Fence posts: infill run = total run − total gate width; posts = (infill run ÷ max post spacing) + 1, plus posts at each gate opening.
- Fence infill: panels = infill run ÷ panel width, rounded up — or, for pickets, infill run ÷ (picket width + gap), rounded up.
- Post-hole concrete: hole volume = π × (diameter ÷ 2)² × depth, summed across all posts and converted to cubic yards.
Worked example
Deck, 12 ft × 10 ft, 5.5 in boards with a 0.125 in gap, 16 ft stock length, 10% waste:
- Row width = 5.5 in + 0.125 in ≈ 5.625 in
- Rows across a 10 ft (120 in) width ≈ 120 ÷ 5.625 ≈ 21.3 → 22 rows
- Board linear feet = 22 rows × 12 ft = 264 ft, + 10% waste ≈ 290 ft
- Stock boards = 290 ft ÷ 16 ft ≈ 18.2 → 19 boards
Result: roughly 19 stock deck boards at 16 ft each for the decking surface alone.
Measuring tips
- Use a board's actual face width (measure it, or check the product label) — "5/4×6" decking is narrower than its nominal size suggests.
- Measure the fence run by following the actual planned fence path, including corners, not a straight-line property distance.
- Confirm your local frost-depth footing minimum with your building department before finalizing post-hole depth.
- Total the width of every planned gate opening separately so it can be excluded from the infill run.