Exterior calculators
Fences, decks, roofing and siding.
- Fence CalculatorEstimate a wood fence: posts, rails, pickets (gates included), concrete bags per post hole, hole base and material cost for privacy or picket fences.150 ft privacy fence → 22 posts
- Roof Pitch CalculatorConvert rise and run, pitch or angle to roof pitch (x:12), degrees, percent slope and pitch multiplier, get rafter length, and see which roofing the IRC allows.6 in rise per 12 in run → 6:12 = 26.57°
- Roofing CalculatorAsphalt shingle roof estimate from size and pitch: squares, bundles, starter, ridge cap, underlayment (incl. wind design), ice barrier, drip edge, nails, cost.40 × 30 ft gable at 6:12 → 45 bundles
About these calculators
The fence calculator counts posts, rails, pickets and concrete bags for a wood fence, gates included. The roof pitch calculator converts rise and run or an angle to pitch, degrees, percent slope and rafter length, and the roofing calculator estimates shingle bundles, squares, underlayment, ice barrier, drip edge and nails for an asphalt shingle roof.
How to measure
Walk the fence line and measure every side, including gate openings. For a roof, measure the outline at the eave edges, meaning the house plus the overhangs. Measure level on the ground, never along the slope. The pitch takes care of that. To find the pitch, hold a level under a rafter in the attic, mark 12 inches along it and measure straight up to the rafter.
Before you start
- Call 811 or file online with your state 811 center a few business days before you dig post holes, and wait the time your state requires. 811 does not mark private lines such as sprinklers or lines to a shed, but a private locator can.
- Cities, counties and HOAs often have their own fence rules - check them before you buy materials.
- Ask your building department whether wind design is required where you live and whether an ice barrier is required. Both change the underlayment.
- Roof work is work at height: keep off wet, icy or mossy roofs, and hire a roofer for work on steep or high roofs.