Construction

Decking Calculator

Estimate deck boards, linear decking, face screws or hidden clips, starter clips, fastener packs, and optional material cost for a deck surface.

Inputs

Adjust your numbers

Results update as you type.

Enter length and width, or leave them blank and enter total area for an irregular deck. Optional price fields add a cost estimate.

Measurement units (required) Choose whether dimensions are entered in ft/in or m/mm.

Deck length Long deck dimension. Leave blank if using total area only.

Deck width Short deck dimension. Leave blank if using total area only.

Deck area override Use for L-shaped or irregular decks; overrides length × width when positive.

Board nominal size (required) Select nominal size; the calculator uses typical actual face widths.

Board length (required) Length of each board: feet in imperial mode, meters in metric mode.

Joist spacing (required) On-center spacing. Metric mode still chooses common 12/16/24 in spacings and converts internally.

Board layout angle (required) Diagonal applies a 15% layout factor; herringbone/chevron applies 30% before the waste percentage.

Fastener type (required) Choose face screws or hidden clips; the inactive fastener output is left blank.

Gap between boards (required) Imperial: inches. Metric: millimeters. Typical dry install gap is about 1/8 in / 3 mm.

Waste factor (%) (required) Use around 10% for straight rectangular layouts; 15–20% for diagonal or picture-frame patterns.

Price per board Optional. Adds board cost to the material estimate.

Fastener pack size Optional. Enter screws or clips per box to estimate packs to buy.

Fastener pack price Optional. Multiplies fastener packs by pack price.

Results

Live answer

Boards to order —

Deck area —

Boards before waste —

Linear decking —

Screws —

Hidden clips —

Starter clips —

Boards per row —

Fastener packs —

Material cost —

How it works

Enter your deck dimensions and board choice. The calculator multiplies length by width for total area, divides by each board's coverage width (face width plus the gap), and rounds up for board count. Diagonal and herringbone layouts apply a layout factor before waste; the screw or hidden-clip count comes from how many joists each board crosses.