Trade & Construction

Deck Board Calculator

Trade & Construction

Deck Board Calculator

Live answer31 boards25 rows · 148.5 m running

Deck length (m)Length of the deck in the direction the boards run.Deck width (m)Width to be covered across the board rows.Board face width (mm)Visible board width, not including the gap.Gap between boards (mm)Planning gap used between board rows.Stock board length (m)Supplier stock length used to estimate pieces to buy.Waste allowance (%)Allowance for trimming, butt joints, defects, pattern layout and spares.Price per stock board (optional)

Live result31 boards25 rows · 148.5 m running

Formula used

Module width = board width + gap. Board rows = ceiling(deck width ÷ module width). Running metres = board rows × deck length. Running metres with waste = running metres × (1 + waste percent ÷ 100). Stock boards = ceiling(running metres with waste ÷ stock board length). Optional material cost = stock boards × price per board.

This is the method behind the answer, so the result can be checked rather than simply trusted.

Live math canvas

Your numbers, formula and explanation together

Deck Board Calculator: 31 boards. 25 rows · 148.5 m running

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Module width = board width + gap. Board rows = ceiling(deck width ÷ module width). Running metres = board rows × deck length. Running metres with waste = running metres × (1 + waste percent ÷ 100). Stock boards = ceiling(running metres with waste ÷ stock board length). Optional material cost = stock boards × price per board.

Apply the formulaModule width = board width + gap. Board rows = ceiling(deck width ÷ module width). Running metres = board rows × deck length. Running metres with waste = running metres × (1 + waste percent ÷ 100). Stock boards = ceiling(running metres with waste ÷ stock board length). Optional material cost = stock boards × price per board.31 boards25 rows · 148.5 m running

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Deck length: 5.4 m
Deck width: 3.6 m
Board face width: 140 mm
Gap between boards: 5 mm
Stock board length: 4.8 m
Waste allowance: 10 %
Price per stock board: 0 optional

Resulting answer

31 boards

25 rows · 148.5 m running

Answer: 31 boards
Live support: 25 rows · 148.5 m running

Assumptions used

What this answer assumes

Surface board estimate only. Make a cut plan before purchase if board joins, borders or diagonal layouts matter.

Deck length and width are entered in metres; board width and gap are entered in millimetres.
Boards are assumed to run along the deck length and repeat across the deck width.
The gap is used for row spacing arithmetic only; follow the board manufacturer and local conditions for real expansion gaps.
The result estimates surface decking boards only. It excludes substructure, joists, bearers, posts, fixings, fascia, stairs, railing, waterproofing, coatings and code requirements.
Stock boards are rounded up by total running metres; exact stagger pattern and join layout may change the real cut list.

Master’s Tip

How to use the result well

Master’s Tip: decide board direction and join pattern before ordering. A total-running-metre estimate is good for an early quote, but picture-frame borders, breaker boards, diagonal layouts and short offcuts can change the purchase count.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

Deck length: 5.4 m
Deck width: 3.6 m
Board face width: 140 mm
Gap between boards: 5 mm

What-if check

Waste and spacing sensitivity

Board orders are sensitive to waste, stock length and gaps. Check these rows before treating the result as a purchase list.

Waste	Linear metres	Stock boards
0.0%	135.0 m	29
5.0%	141.8 m	30
10.0%	148.5 m	31
15.0%	155.3 m	33

Gap	Rows	Boards
3.0 mm	26	33
5.0 mm	25	31
7.0 mm	25	31

Visual proof

Rows × board length

The sketch shows why decking is a linear-material estimate: repeated rows across the width multiplied by the board run length.

Visual grid

This result measures part of the space you live in

Length, area, volume and material estimates are grid problems too: measure the space, account for edges and allowances, then turn the pattern into a number you can use.

Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars

Measured output31 boards

Space calculations turn a real surface, room, run or volume into cells, edges and allowances that can be quoted, ordered or checked.

31 boards25 rows · 148.5 m running

Inputs

Deck length: 5.4 m
Deck width: 3.6 m
Board face width: 140 mm
Gap between boards: 5 mm
Stock board length: 4.8 m
Waste allowance: 10 %
Price per stock board: 0

Method

Deck width 3.6 m is 3,600 mm. A 140 mm board plus 5 mm gap gives a 145 mm module. Rows = ceiling(3,600 ÷ 145) = 25. Running metres = 25 × 5.4 = 135 m. Add 10% waste: 148.5 m. With 4.8 m stock boards: ceiling(148.5 ÷ 4.8) = 31 boards.

Assumptions

Deck length and width are entered in metres; board width and gap are entered in millimetres.
Boards are assumed to run along the deck length and repeat across the deck width.
The gap is used for row spacing arithmetic only; follow the board manufacturer and local conditions for real expansion gaps.
The result estimates surface decking boards only. It excludes substructure, joists, bearers, posts, fixings, fascia, stairs, railing, waterproofing, coatings and code requirements.

Notes

Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.