Cable size calculators compared
This table sets nine cable size calculators side by side. Each cell is one fact, with its source and the date it was read.
The AmpSize row is computed from the code that runs this site. The other rows come from each public page.
9 calculators, 7 facts
| Tool | Calculators | Guides | AS/NZS 3008 edition cited | Price | PDF or report | NZ part 3008.1.2 | Mobile app |
|---|---|---|---|---|---|---|---|
| AmpSize | 53 (measured) | 29 worked guides published (measured) | AS/NZS 3008.1.2:2017, 3008.1.1:2025, 3008.1.1:2017 (measured) | Free. Pro is NZ$5 a month or NZ$45 a year. (measured) | Free. PDF reports with an AmpSize footer line. (measured) | Yes, 3008.1.2:2017 (measured) | Android, in closed testing on Google Play (measured) |
| jCalc | 16 (opened) | No guide section linked from the home page. Method notes sit on each calculator page. (opened) | AS/NZS 3008.1.1:2025 and 2017, AS/NZS 3008.1.2:2017 (opened) | Free version. A paid subscription adds save, open and report lists. (opened) | A report on the free version carries a watermark. A subscription removes it. (opened) | Yes, 3008.1.2:2017 (opened) | None found on the home page (opened) |
| ElecCalc | 25 (opened) | Yes, a guides section (opened) | AS/NZS 3008.1.1:2025 (opened) | Free. The site says no paywall and no subscription. (opened) | A PDF report download on the cable sizing page. The site says no watermark. (opened) | Not named on the home page (opened) | An iOS app is linked from the home page (opened) |
| ElecASelecas.com.au now redirects to scaleset.com.au. The facts below are from that site. | 18 or more (the site says "18+") (opened) | Yes, design guides (opened) | AS/NZS 3008.1.1:2025 (opened) | Free. Pro and AI Pro are paid plans. (opened) | Branded PDF reports, free with a free account (opened) | New Zealand is named. 3008.1.2 is not named on the home page. (opened) | No app store app. The site says to add it to the home screen on iOS or Android. (opened) |
| ELEK | 5 named on the calculators page: cable sizing, arc flash, maximum demand, cable pulling, protection coordination (opened) | Method text and a video on the NZ calculator page (opened) | AS/NZS 3008.1.2 on its NZ page. No year shown. (opened) | Free plan with 100 cable sizing calls a day. Paid plans from AUD 99 to AUD 650 a year. (opened) | Branded PDF reports on the Premium and Professional plans (opened) | Yes, an AS/NZS 3008.1.2 page (opened) | No app. The web software adapts to a phone screen. (opened) |
| CableHero | 1 free cable size page reviewed (opened) | An FAQ on the calculator page (opened) | AS/NZS 3008. No part or year shown. (opened) | Free estimate. A full report needs registration. A free trial and paid plans are linked. (opened) | A full calculation report after registration (opened) | Not named on the calculator page (opened) | None found on the calculator page (opened) |
| WireWriteThe WireWrite home page body was empty when fetched on 1 Oct 2026, so most facts here are from 28 Sep 2026. | 3 free calculators named: conductor, maximum demand and voltage drop (opened) | Not established. The page body was empty when fetched. (opened) | AS/NZS 3008:2017 (NZ cable sizer) (snippet) | Free calculators. Digital CoC, ESC and CoV certificates are paid. (opened) | Digital certificates (paid). Calculator export not established. (opened) | Yes, an NZ cable sizer (snippet) | An installable web app (PWA) is described (opened) |
| calculate.co.nz | 2,465 on all subjects (the site’s own count) (opened) | 433 on all subjects (the site’s own count) (opened) | AS/NZS 3000:2018. No AS/NZS 3008 edition named. (opened) | Free, no sign-up (opened) | Not found on the page (opened) | Not named on the page (opened) | None found on the page (opened) |
| Firstflex FIRSTCALC | 5 calculators, a cable selection tool and a chemical rating guide (opened) | Not found on the reviewed page (opened) | No AS/NZS 3008 edition named (opened) | Free (opened) | A saved list, emailed with datasheets (opened) | Not named on the reviewed page (opened) | iOS and Android. It works offline. (opened) |
How to read the table
A mark after each fact says how it was read. The date under it links to the page it came from.
"Not found" means the reviewed page did not show it. It does not mean the tool lacks it.
No result from another tool was checked against a licensed standard. Prices and features change, so check the vendor page before you decide.
- (opened)
- Opened: the page was fetched and read on the date shown.
- (snippet)
- Snippet: only a search-result snippet was read on the date shown.
- (measured)
- Measured: computed from the AmpSize code on the date shown.
Three tools in more detail
- jCalc and AmpSize
jCalc and AmpSize compared as cable size calculators for NZ and AU: editions cited, price, reports and guides, each fact with its source and date.
- ElecCalc and AmpSize
ElecCalc and AmpSize compared as cable size calculators for NZ and AU: editions cited, price, reports and guides, each fact with its source and date.
- ElecAS (ScaleSet) and AmpSize
ElecAS, now ScaleSet, and AmpSize compared as cable size calculators for NZ and AU: editions, price, reports and guides, each fact with its source and date.
The comparison pieces
- AmpSize vs jCalc vs free cable sizing tools
Compare AmpSize with jCalc and other free cable sizing tools. One 63 A three-phase submain shows which checks decide a size, and what AmpSize leaves out.
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