This estimator takes the area and width of the deck and presents to you a list of decking options, the number of metres of decking required and more importantly the cost. Please note there is a greater range of decking for decks where the joist spacing is 450mm or less. Also if your deck is has a handrail, your joist spacing needs to be a maximum of 400mm.
Decking estimator for decks
More Information the Decking Estimator
The form above is a powerful tool for presenting a wide range of decking options with the following information:
The decking size (width & height)
The decking type
The length of decking required
The cost of the decking required
How the Decking Estimator works
The decking estimator can estimate the length of decking required by the following steps:
Step 1) Taking the overall width of the deck and dividing this for each product by the decking width with a 3mm gap. The number is rounded up to the next whole number.
Step 2) The area is divided by the no. of decking boards. This gives the average length of a decking board.
Step 3) The average length of decking required in step 2 above is multiplied by the no. of decking boards across in step 1
Step 4) The total in step 3 is then increased by the wastage amount. This gives the total length of decking for each product.
Step 5) The total in step 4 is then modified by the unit price to give the extended (total) cost.
Sample decking options for a 30M² deck with 5% wastage with a maximum joist spacing of 450mm
For more information from a vendor, please click on the link on the prices.
POA = Price on application
Many of the products are available from the venders in a quantity per length, and are specified in this table as a cost of per metre. Please note that many of these products may not be sold on a metre basis.
Please allow for delivery when calculating costs, this table does not include delivery costs.
This table does not take into account of the regional availability of materials in differing locations.
Whilst the greatest care has been taken to ensure the accuracy of this information, prices do change and mistakes, though seldom do occur.
All prices are in New Zealand dollars and include GST (goods and services tax), though some of the product pages this website links to, do not include GST.
Material prices last updated: Friday 7 November 2025
Disclaimer: Whilst this website contains a lot of information on the design of decks which has been produced with the highest level
of professional care, ROBO Deck Designer, ROBO Design Solutions or Paul Roberts (the developer of this website) does not accept any responsibility for
the accuracy of the information on this website. This website is intended as a guide only, please refer to the New Zealand building code for the
appropriate regulations.
