Construction
Stair Stringer Calculator
Riser count, actual rise, and total run for stairs.
Free to use — no sign-up or login.
Number of risers
Actual rise (in)
Treads
Total run (in)
Amortization schedule
| # | Date | Payment | Principal | Extra | Interest | Balance |
|---|---|---|---|---|---|---|
Risers are the total rise divided by the preferred riser, rounded to a whole number. Total rise 100 in and a 7 in preference gives 14 risers. Actual rise is 100 / 14 = 7.14 in. Treads are one fewer: 13. Total run is 130.00 in.
Roof slope is the roof pitch calculator. This is a straight run, not a code check.
A straight run
The profile is repeated treads and risers. Landings, winders, and nosings are not in the count.
Actual rise can differ from the preference
Rounding the riser count changes the actual rise so the steps still add up to the total rise.
Worked example: 100 inch rise
Total rise 100 in, preferred riser 7 in, tread 10 in. Risers 14, actual rise 7.14 in, treads 13, total run 130.00 in.
\[ n = \mathrm{round}(100/7) \]
Frequently asked questions
What does the stair stringer calculator measure?
100 inches at a 7 inch preference is 14 risers and a 130.00 inch run.
How many decimal places does stair stringer calculator show?
100 inches at a 7 inch preference is 14 risers and a 130.00 inch run. Lengths, areas, volumes, and money use two decimals. Purchase counts are whole numbers.
Does stair stringer calculator include waste?
No waste and no code check. Confirm the rise and tread locally.
Can stair stringer calculator mix units?
No. stair stringer calculator expects every input in the unit printed on its label.
Is stair stringer calculator a code or structural check?
No. stair stringer calculator is a quantity estimate. Local rules and site conditions stay outside the formula.
References
Assumptions and limitations
Straight run only. It is not a building-code check, and it ignores landings and nosings.