Calculating space for stair construction

Most stair construction in smaller homes is easy with the right formula. Many modern stairs will have landings because of the room it saves. Plus, landings are very popular right now.
stair landing

Basic stair construction is basic mathematics. How many steps will you need to elevate yourself to the next level of your home?

Measure the height from floor one to floor two and divide by 7. (Seven being the height of average stair risers) Example: 108 inches divided by 7 equals 15.428. You'll need 15 risers to reach the second floor. (Remember to include the thicknesses of the joists and floor boards in your height measurement.)

Next, divide 108 by 15 and you get about 7 3/16 inches. This is the height each stair riser needs to be.

A typical tread is right around 10 inches. The amount of treads will be one less than the amount of risers(14 treads), to find the total run or length of a single run staircase, multiply 10 by 14 and that tells you your stairway will be 140 inches long. The width of typical stairs is four feet. A space of 140" x 48" will accommodate the staircase in this example.

build a stair stringer

The equation for determining the amount of risers is standard for any style of stairs, however, figuring how much floor space your staircase will take up depends on which design you choose.

building stairs

framing stairs

Stairs with landings use the same mathematical formula. You just measure from the floor up to the top of the landing and calculate that distance. Then you measure from the landing up to the second floor for second measurement.

Will you have a long single flight of stairs or will you divide the ascension with a landing. Perhaps a circular staircase is what you desire or a single flight with a gentle curve.

Will your stairs be open to the second story ceiling? Or will you utilize the dead space above? Below are some examples of staircases.

Dual Landings Staircase

180 degrees Curved Staircase staircases

Modern Split Level Entryway modern staircase

Switch-back with landing modern stairs

Gentle Curve Single Flight curved stairs

circular stairs

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