Stairs & stringers · Guide 1 of 9 · 3 min readUpdated
How to measure total stair rise
Understand why finished elevations control stair comfort, how riser count affects the footprint, and when to confirm measurements before cutting.
Start with the surfaces your feet will use
People walk on the finished treads and landings, so equal framing dimensions alone do not guarantee equal steps. A floor finish added later can make the first or last rise different from the rest. Establish the final upper and lower elevations even when you are standing on unfinished framing.
Riser count is also a space decision. For the same total height, more risers produce a smaller individual rise but generally need more treads and a longer footprint. Fewer risers make each step taller. Compare only arrangements that meet the project requirements, then check their landings, headroom and available run together.
Example: tile has not yet been installed below the stair
Include the complete planned tile buildup in the lower finished elevation, rather than measuring to the bare slab and promising to adjust the last cut. If the finish specification changes, revisit the total rise before copying the stringer pattern. This is much easier than correcting an odd first step after installation.
Start with finished surfaces
Total rise is the vertical distance from the finished lower walking surface to the finished upper landing or deck surface. It is not the height to the bottom of the framing, and it is not the length along the slope.
If flooring, decking, tile, or another finish has not been installed, include its final thickness in your measurement. A small miss at this stage gets divided across every riser—or shows up as an awkward first or last step.
A reliable measuring routine
- Establish the finished upper landing elevation with a level, laser, or straight reference board.
- Measure vertically down to the finished lower surface, keeping the tape plumb.
- Measure in more than one location when the lower surface may slope or vary.
- Record the measurement precisely; do not round it to a convenient whole number.
- Confirm all planned finish thicknesses before entering the rise in the calculator.
For an exterior stair landing on uneven grade, the stair needs a properly designed, stable lower landing. Do not treat loose or sloped soil as the finished reference surface.
Turn the measurement into equal risers
Choose an allowable maximum riser for your project, then let the calculator find a whole number of risers and divide the total rise evenly.
Riser count = round up (total rise ÷ maximum riser) Exact riser = total rise ÷ riser count
Always verify the resulting dimensions against the building code and authority that apply where you are building.
Worked check: 108 inches of finished rise
With a 7.75-inch maximum, 108 ÷ 7.75 requires 14 risers. Each is 108 ÷ 14 = 7.714285… inches. The nearest 1/16-inch display is only an approximation.
Fourteen repeated 7 11/16-inch rises total 107 5/8 inches, leaving a 3/8-inch error. Use the decimal setting, verify cumulative elevations from one datum, and test the actual first and last finished rises.
Technical references
Confirm the current product literature and requirements for the material and assembly being installed.