Roof and deck calculators

Work out pitch, rafters, shingles, decking, stairs and footings. Every answer shows its formula.

Roof

Pitch, angle in degrees, slope percent and rafter length.

Roof square footage from house size and pitch, no climbing.

Common rafter length, overhang tail and cut angles.

Bundles, squares, underlayment rolls, nails and ridge cap.

Deck boards, joists, screws, hangers, posts and footings.

Number of steps, riser height, total run and stringer length.

Bags of concrete for post holes, tube forms and small pads.

How many balusters, and the exact even gap between them.

The formula is on the page. Every calculator lists the math it uses, so you can see how each answer is made.
One example is worked by hand. Follow it with a pencil and you will land on the same number.
Nothing leaves your device. The math runs in your browser. There is no sign-up and nothing is saved.