Free Calculators for Kiwi Projects
Planning a project just got easier.
Whether you're building a fence, laying a deck, or pouring concrete, our easy-to-use calculators help you get the quantities spot on before you hit the yard. Choose from our Fence Calculator, Decking Material Calculator, or Concrete Volume Calculator to work out potentially how much timber, hardware, concrete or fixings you'll need.
Designed for New Zealand builders, DIYers, and landscapers, these tools take the guesswork out of ordering and help reduce waste, save money, and keep your build on schedule.
Get Your Project Right, First Time
With Our Smart Building Material Calculators.
Fencing Calculator
Figure out how many posts, rails, palings, and bags of concrete you’ll need based on your total fence length, paling width, and post spacing. Quick, accurate and simple.
Decking Calculator
Estimate how many decking linear metres and total screws your job will need. Just enter your deck size and board type to get a tailored material list in seconds.
Concrete Calculator
Work out the exact volume of concrete required for slabs, footings, and holes. Get estimates in cubic metres and bag quantities based on the size and depth you enter.
Address:
32 Henderson Valley Rd
Henderson
Auckland, 0612
Henderson
Auckland, 0612
Frequently asked questions
Here are some common questions about our company.
Simply select the fence post calculator, enter the post size, hole depth, and diameter, and the tool will give you the exact volume required. We recommend allowing an extra 10% for wastage and uneven ground.
Our calculators give you a very close estimate based on standard timber sizes and spacing used in NZ. Actual quantities may vary depending on your specific design, timber type, or site conditions.
Yes, it’s best practice to order slightly more than the exact result. We suggest adding 5–10% extra for offcuts, wastage, and any unexpected changes during installation.
The tools use common NZ timber sizes stocked at WBS Henderson. For example, decking is calculated on standard 90mm wide decking boards through to the wide boards at 140mm. And fence posts are based on 75mm, 100mm square posts through to the round SED Poles.
Yes. Whether you’re a DIYer building a small deck or a builder managing a large fencing job, these tools are designed to give you fast, reliable estimates for material planning.
You can order directly from WBS Henderson. Our trade store in Henderson stocks fencing, decking, and concrete supplies, and our team can help you finalise your order. Contact us or visit in-store for friendly advice.
Got Questions?
Not quite sure what you need, or how much of it? No worries, just flick us a message! Whether you’re stuck on post spacing or just need a second opinion, we’re here to help. We aim to get back to you within 24 hours (Sunday excluded of course; the boss insists we get one day off to crack into our own DIY jobs at home).
Fill in the below and we will get back to you in a jiffy.