Right Triangle Calculator

http://www.csgnetwork.com/righttricalc.html
The purpose of this calculator is to verify that your measurements of the staircase are correct. You can use it on a computer or on a smart phone.

Enter any 2 of the 4 values, height, length, run, and angle.

A = Height (H)
B = Length (L)
C = Run (R, or nose to floor)
Angle A or B

For example:
Enter A (Height) and C (Run) and click Calculate. You will get B (Length) and Angle.
Click Clear Values.
Enter C (Run) and Angle. You will get B (Length) and C (Run).
Etc.

Your values should agree within about an inch. Your Angle should be correct within 1 degree.

If they do not agree, try using the sum of the risers and/or the sum of the treads (if they are different) instead of H and L.