Stair Calculator
Stair Calculator | Accurately calculate stair dimensions for your construction project. Our easy-to-use tool helps professionals and DIY enthusiasts plan perfect stairs every time.
Basic Stair Calculator
Calculate fundamental stair dimensions quickly for standard installations.
Calculation Results
Number of Steps
–
Riser Height
–
inches
Tread Depth
–
inches
Total Run
–
inches
Note: For comfortable stairs, follow these guidelines:
- Riser height should be between 6-8 inches
- Tread depth should be between 9-11 inches
- Ideal relationship: 2×Riser + Tread ≈ 25 inches
Comprehensive Stair Calculator
Advanced calculations for complex stair designs and precise measurements.
Advanced Calculation Results
Number of Steps
–
Riser Height
–
inches
Tread Depth
–
inches
Stringer Length
–
inches
Stair Angle
–
degrees
Step Overhang
–
inches
Professional Tips:
- Stringer length is measured along the slope
- Ideal stair angle is between 30°-35°
- Minimum headroom is typically 80 inches (6’8″)
- Nosing improves safety and comfort
Fraction to Decimal Conversion
| Fraction | Decimal | Fraction | Decimal | Fraction | Decimal |
|---|---|---|---|---|---|
| 1/16 | 0.0625 | 1/4 | 0.25 | 3/4 | 0.75 |
| 1/8 | 0.125 | 5/16 | 0.3125 | 13/16 | 0.8125 |
| 3/16 | 0.1875 | 3/8 | 0.375 | 7/8 | 0.875 |
| 1/5 | 0.2 | 7/16 | 0.4375 | 15/16 | 0.9375 |
| 1/3 | 0.333 | 1/2 | 0.5 | 1 | 1.0 |
| 2/5 | 0.4 | 9/16 | 0.5625 | 1 1/8 | 1.125 |
| 3/5 | 0.6 | 5/8 | 0.625 | 1 1/4 | 1.25 |
| 2/3 | 0.666 | 11/16 | 0.6875 | 1 1/2 | 1.5 |
Usage Tip: Use this table to convert fractional measurements to decimals when using our stair calculator. Most building measurements use fractions, but calculations require decimals.