Deck Board Planner
Estimate parallel decking boards with spacing and extra allowance.
Your inputs
Calculation results
Formula & assumptions
Rows = ceiling((deck width + gap)/(board width + gap)); boards run the full deck length.
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Deck Board Planner
Estimate parallel decking boards with spacing and extra allowance.
- Enter deck width, deck length, board width, gap, extra boards using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Deck width: 4 meters Deck length: 5 meters Board width: 140 millimeters Gap: 5 millimeters Extra boards: 10 percent Board rows: 28 Rows with allowance: 31 Total board length · meters: 155
Questions & answers
What does Deck Board Planner calculate?
Estimate parallel decking boards with spacing and extra allowance.
Which units should I enter?
Deck width uses meters. Deck length uses meters. Board width uses millimeters. Gap uses millimeters. Extra boards uses percent. Convert values to these units before calculating.
Which formula does it use?
Rows = ceiling((deck width + gap)/(board width + gap)); boards run the full deck length.
What does the included example show?
Deck width: 4 meters; Deck length: 5 meters; Board width: 140 millimeters; Gap: 5 millimeters; Extra boards: 10 percent. Result: Board rows = 28; Rows with allowance = 31; Total board length · meters = 155.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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