How to Use the Deck Slope Calculator
- Enter the vertical rise (height) of your deck in inches in the "Rise" field.
- Enter the horizontal run (length) of your deck in feet in the "Run" field.
- Select your preferred slope type from the dropdown menu:
- Rise/Run: Standard slope measurement showing rise per unit run
- Percentage: Slope expressed as a percentage (e.g., a 5% slope rises 5 inches for every 100 inches of run)
- Angle: Slope measured in degrees from horizontal
- Click the "Calculate" button to see the results.
- Use the "Reset" button to clear all inputs and start over.
Deck Slope Recommendations
A proper deck slope is essential for water drainage and preventing water damage. Typical deck slopes range from:
- 1/8 to 1/4 inch per foot (2% to 4%) for residential decks - Ideal for moderate climates
- 1/4 to 1/2 inch per foot (4% to 8%) for areas with heavy rainfall
- Minimum code requirement is usually 1/8 inch per foot (2%)
Important Notes
The slope of your deck affects both its appearance and functionality. Too flat, and water will accumulate; too steep, and walking may become difficult. Always check your local building codes for specific requirements in your area.