Calculated result
14risers
Risers to plan
Formula
FRM-STAIR-0017.5 in
Actual riser
13 treads
Treads
130 in
Total run
Lumber & framing calculator
Stair calculator
Preliminary riser count, tread run and stringer length from total rise and target step dimensions.
Reviewed formula · v1.0.0
Project inputs
Enter field measurements. Unit conversion happens before the reviewed formula is applied.
All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.
Transparent cost view
Use visible planning values, then replace them with actual job costs before quoting.
Material cost$1,190
Direct cost$1,580
Overhead + contingency$158
Markup + tax$209
Estimated project total$1,947
How this calculator works
A transparent stair calculator takeoff.
This calculator converts a finished floor-to-floor rise into a whole number of risers, then reports actual riser height, tread count, total run and stringer length from the target going.
Worked example. Example: a 105 in total rise with a 7.5 in target riser produces 14 risers at 7.50 in. Thirteen 10 in treads make a 130 in run and a 13.93 ft stringer; 2R + T equals 25.00 in.
- 1. Measure the finished floor-to-floor rise, not the rough opening alone.
- 2. Enter a target riser and tread, then review the resulting actual riser and 2R + T check.
- 3. Verify headroom, nosing, stringer stock, guards and local requirements independently.
Need the broader workflow? Read the lumber & framing planning guide.
Questions
Common questions about this stair calculator.
Does this meet building code?
No. Riser, tread, nosing, headroom and guard rules vary by jurisdiction. Use this as geometry planning only.
Why is 2R + T shown?
Carpenters often check 2 × riser + tread as a comfort range. It is a planning check, not an approval.