Deck Board Calculator
Estimate deck board count and total linear metres from deck dimensions, board width, gap and board length.
Set your values
Adjust the values, then calculate your result.
How to use Deck Board Calculator
- Enter the measurements or amounts in the fields above.
- Check that dimensions, rates and units match the labels.
- Select “Calculate deck boards” to see a clear estimate and the formula used.
How the deck board calculator works
Board rows = deck width ÷ board face width plus gap, rounded up. Total linear metres = rows × deck length with the selected allowance; stock boards are rounded up.
Check your measurements and assumptions
This estimate assumes parallel boards spanning the deck length. It omits joists, picture framing, stairs, fasteners, structural design and unusable offcuts; verify the framing plan separately.
Review the estimate before you act
Compare this result with an independent measurement, supplier quote or institution guidance when the decision matters. Confirm that the units and assumptions match the labels above, and update the inputs when the conditions change. Keep a note of the values used so you can reproduce the estimate later. This calculator is a planning aid and does not replace professional, product-specific or local guidance.
How many deck boards do I need?
Estimate the number of rows across the deck, multiply by the deck length and divide the total by your stock board length.
Is input uploaded?
Processing takes place in your browser. This tool does not send your input or selected files to a conversion API.