What is a good rise and run for stairs?

Most interior stairs land between 150 and 190 mm of rise with 250 to 290 mm of run. The classic comfort rule is 2 × rise + run, which should fall between 610 and 650 mm. The table above shows common combinations that satisfy it.

How many risers for a 2800 mm rise?

At a 175 mm tread rise: 2800 ÷ 175 = 16 risers. On a standard mount the finished floor acts as the final tread, so the stringer gets 16 rises and 15 cut treads.

What angle should a staircase be?

Comfortable interior stairs sit between 30° and 35°. Deck stairs often run shallower for a gentler climb, while tight utility stairs can push toward 38°.

Does this stair calculator handle flush mount?

Yes. Standard mount treats the upper floor as the last tread; flush mount adds the top tread run because the final tread lands level with the upper floor. The demo returns options for both.

Stair Calculator for Rise, Run and Treads

How this stair calculator works

Start with the finished-floor to finished-floor rise. StructCalc divides that rise by its target stair rise, then returns three nearby layout options: fewer steps, the ideal layout and more steps. Each option gives tread rise, tread run, stair angle and total run.

The standard mount option treats the top floor as the final step. Flush mount includes the extra run because the top tread lands flush with the upper level. That distinction matters when you are checking available floor space or marking a stair opening.

Example stair layout

For a total rise of 2800 mm, the calculator returns a set of practical stair layout options. You can compare the total run and angle before committing to a stringer layout. On site, that makes it easier to check whether the stair fits the available opening and whether the rise and run feel reasonable.

Common stair layouts

Rise and run combinations that come up on real builds, with the stair angle and the 2 × rise + run comfort check. Between 610 and 650 mm, a stair feels natural under foot.

Tread rise	Tread run	Stair angle	2 × rise + run
165 mm	290 mm	29.7°	620 mm
175 mm	280 mm	32.0°	630 mm
180 mm	270 mm	33.7°	630 mm
190 mm	260 mm	36.2°	640 mm
200 mm	250 mm	38.7°	650 mm

For a 2800 mm total rise, a 175 mm tread rise works out to exactly 16 risers — one of the layout options the demo above returns.

Stair calculator FAQ

What is a good rise and run for stairs?: Most interior stairs land between 150 and 190 mm of rise with 250 to 290 mm of run. The classic comfort rule is 2 × rise + run, which should fall between 610 and 650 mm. The table above shows common combinations that satisfy it.
How many risers for a 2800 mm rise?: At a 175 mm tread rise: 2800 ÷ 175 = 16 risers. On a standard mount the finished floor acts as the final tread, so the stringer gets 16 rises and 15 cut treads.
What angle should a staircase be?: Comfortable interior stairs sit between 30° and 35°. Deck stairs often run shallower for a gentler climb, while tight utility stairs can push toward 38°.
Does this stair calculator handle flush mount?: Yes. Standard mount treats the upper floor as the last tread; flush mount adds the top tread run because the final tread lands level with the upper floor. The demo returns options for both.

Need this on site?

StructCalc for Android includes stair, rafter, baluster, raked wall, square check and measurement tools with a faster jobsite workflow. Use the web demo for a quick number, then use the mobile app when you need the full calculator set offline.

Get StructCalc on Google Play