How to Calculate Stair Rise and Run
Quickly find the riser height, tread width, and total number of steps based on total rise.
Building stairs that are safe and comfortable to climb requires precise mathematics to ensure every riser height and tread width is within commercial and residential building code.
The Rise Ratio Rule
A common rule of thumb for comfortable stairs is that 2 RISERS + 1 TREAD should equal between 24 and 25 inches. Standard residential risers are usually between 7 and 7.75 inches high.
Layout Precision
Once you have your dimensions, mark your 2x12 stringer carefully using a framing square and stair gauges. Any error in measurement will accumulate, causing a 'trip hazard' at the top or bottom step.
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