Home › Rafter span calculator

Made in NZ · For NZ builders

Rafter spans to NZS 3604

Rafter and purlin spans for the pitch, roof load and wind zone — then carried into the full roof take-off and the priced quote.

No credit card · Cancel anytime · Works offline on site · Flat NZD pricing

Roof framing, sized to NZS 3604

Rafter spans in New Zealand come off NZS 3604: the timber size and grade, the spacing, the roof load (light vs heavy roof) and the wind zone all change how far a rafter can go before it needs a bigger member or a purlin. Reading it off the tables for every pitch and span is slow.

Toolie takes the roof from a plain-English description or a PDF plan, sizes the rafters, purlins and ridge to NZS 3604 for the load and the wind zone (which it derives from the site address), runs the rest of the roof take-off and prices it off a real NZ pricebook.

It’s part of the quote, not a separate tool

In Toolie this isn’t a one-off calculator — it feeds the actual priced quote and the build programme. Describe the job or drop in a PDF plan and Toolie runs the take-off, applies NZ site intelligence and prices it off a real NZ pricebook.

More on-site calculators

See all 16 builder calculators, the full feature guide, or how Toolie quotes a job.

Common questions

How far can a rafter span under NZS 3604?

It depends on the timber size and grade, the spacing, the roof load (light or heavy) and the wind zone. Toolie sizes the rafters and purlins to NZS 3604 for your roof and site rather than you reading the tables by hand.

Does it include purlins and the ridge?

Yes - the take-off covers rafters, purlins, the ridge and the rest of the roof framing, sized to NZS 3604.

Does it price the roof?

Yes - Toolie prices the roof framing and the rest of the job off a real NZ pricebook with regional rates.

Quote, comply and get paid — in one place

Start free today. NZS 3604, H1, Healthy Homes & CCA 2002 built in. One flat price for your whole crew.

Start your 14-day free trial →