Steps, riser, run & stringer, plus a baluster spacing calculator. Offline.
Planning a staircase and its railing? Stair Calculator works out the stairs from your floor-to-floor
rise, then spaces the balusters for the railing: a free baluster spacing calculator built in, offline.
STAIRS
Enter total rise, target riser and tread depth, and get:
• Number of steps (risers) and the exact riser height
• Number of treads and the total run (horizontal length)
• Stringer length (the sloped board to cut)
BALUSTER SPACING
Enter the section length, the baluster width and your max gap, and get:
• How many balusters you need: the fewest that keep every gap under the max
• The exact gap and the on-centre spacing
• Where the first baluster goes, from the post face to its edge and to its centre
• A list of centre marks from the post face, and the spacer block to cut
• Level runs (decks, landings, balconies) and stairs: on a stair the gap is solved level between
the upright balusters, and the marks are given along the sloped rail, with balusters per tread
• Length measured between post faces, post centre to centre, or over the outside of the posts
• One tap from your staircase: its own rise and run fill the stair mode
• Inches with fractions to 1/16 (type 3 1/2 or 3-1/2) and millimetres, both shown side by side
The max gap starts at 4 in (100 mm in metric), a common code limit. Codes differ, so check yours: the
app gives no legal advice.
Works in centimetres, millimetres or inches. Works offline, no account: your numbers stay on your
phone. For carpenters, deck builders and DIYers laying out stairs and railings that are safe and even.
Stair calculator, staircase calculator, stringer length, rise and run, riser height, baluster spacing
calculator, spindle spacing, deck railing — from Fernhart Labs.