Support

Stairwright lays out a straight stair and the stringer cuts for it, and, with the Landings purchase, stairs with a landing. Enter decimal inches (8 ft 4 in = 100); results update as you type.

Checks use the 2021 International Residential Code, section R311.7. States and cities amend these limits. Confirm with your local building official before you cut.

Using the screens

Layout

Enter the floor-to-floor rise and the tread depth you want. The list starts at the fewest risers that keep each riser at or under 7 3/4" and adds three more counts. Tap a count to open its stringer.

Fit a gap

Use this when both ends of the stair are fixed. Enter the total rise and the horizontal run available. Run is horizontal between the first and top riser faces, excluding landings. Each count uses the full run, with treads of at least 10". The upper floor is the final step, so 14 risers have 13 treads.

Stringer

Set the tongue of the framing square to the rise and the blade to the tread. Stock width is the actual width of the board (11 1/4" for a 2x12). Throat left is the board remaining under the notches; the app reports it but does not judge whether it is enough. The first riser is shortened by one tread thickness, assuming equal tread thickness and a finished lower floor. Fractions round to 1/16 in; repeating them can change the total rise and run. Use the decimal values to check cumulative marks against the measured totals.

Save and share

Save keeps the stair dimensions and board sizes under a name. Changes in another plan do not change those board sizes. The share button at the top sends a text cut sheet. Headroom inputs use Settings.

Headroom and stairwell opening

Upper floor depth is the framing, subfloor and finish at the stairwell edge. The opening is measured horizontally from the face of the top riser back over the stair.

Landings (one-time purchase)

For a rise over 12' 7", or a stair that turns. Choose straight, L-shaped or U-shaped, then enter the total rise, tread, stair width and landing depth (and, for U-shaped, the gap between the flights). The app splits the risers between two flights and shows the landing height, each flight's run and the outside size of the stair and landing. Walls, stringers and finishes are not added to that size. Checks cover the riser, tread, width, the 12' 7" rise per flight and the landing depth. Straight stairs, stringers and headroom stay free.

Restoring the purchase

On a new iPhone, or after reinstalling, open Settings and tap Restore purchase. Use the same Apple Account you bought it with. Family Sharing is supported.

If a result looks wrong

Use the contact form (also in the app under ? > Questions) or email us.

Email yuugou.purple@gmail.com with every input you entered, the result shown and the result you expected. Include the app version and your iOS version. A screenshot helps; remove personal information before sending it.

The app works offline. These pages load from the web, and support email goes through your mail provider. The privacy policy covers both.