Our deck design calculator makes it simple to estimate the materials you’ll need for your decking project. Here’s how it works:

Submit Your Input Data

These inputs help the calculator understand the size and structure of your project.

• Enter your deck dimensions such as length and width (in feet).
• Select the deck height (up to 4 feet).
• Choose the joist spacing (in inches).
• Optionally, specify if your design includes a cantilever or 2x12 joists.

View Deck Component Dimensions

After submission, the calculator instantly generates the required deck dimensions.

• It shows the joist span and beam span (in feet and inches).
• It calculates the number of joists and beams needed to support your design.

Get a Detailed Material List

The calculator also provides a complete material breakdown:

• Posts (size and quantity)
• Beams (dimensions and count)
• Joists (dimensions and total boards required)
• A total unit count of all required materials

This makes it easy for you to know exactly what you’ll need before starting construction.