How to measure
- Measure the run length covered by one row of footings.
- Enter the number of footing rows and the maximum spacing for each row.
- Open Advanced settings for an optional footing diameter, depth, bag yield, and price comparison.
Deck Footing Calculator
Plan a regular footing grid and optionally estimate cylindrical concrete volume and bags.
How this deck footing estimate works
Use this calculator for a regular footing grid during early deck planning. It keeps the layout count separate from optional concrete volume so you can review the grid before making structural or excavation decisions.
How the estimate works
Divide run length by maximum spacing and round up to whole spaces. Add one to get footings per row, then multiply by the row count.
Worked example
A 20 ft run at 6 ft maximum spacing has 4 spaces and 5 footings per row. Two rows produce 10 footings before any concrete calculation.
Before you buy
If you enter footing size and bag yield, use the result to compare material quantities. Confirm excavation access, inspection needs, frost depth, and the framing plan first.
Package and supplier details
Soil, frost, loads, beams, drainage, permits, footing shape, bag yield, and local structural requirements can change the final plan.
Assumptions
- Each row uses the same run length and maximum spacing.
- Rows are regular and have the same footing count.
- Concrete volume is optional and uses simple cylindrical footings.
Limitations
This is a planning and layout estimator only. It does not design footings, verify loads, choose depth, or replace permit and structural review.
Questions about deck footing
What does footing row count mean?
It is the number of parallel rows in the grid. Enter the rows shown in your early deck layout.
Can I use the concrete result as a footing design?
No. The optional volume is for material planning from a cylinder size you enter. Frost, soil, loads, and local rules still control the design.
Why does changing maximum spacing change the count?
The run is divided into enough whole spaces to stay within the maximum. A smaller maximum usually creates more spaces and footings.
Related guides
Short, practical help for the next step in this project.