Best Cordless Circular Saws Australia: 18V vs 20V vs 36V Power
Quick summary: For most tradies and serious DIYers, an 18V brushless saw on a shared battery platform (like the Makita DHS680Z 18V circular saw ) covers 90% of framing and decking work. Step up to 36V dual-battery saws like the Makita DHS900Z 36V circular saw only if you're cutting hardwood decking boards or thick engineered beams all day. Bunnings stocks the mainstream brands at competitive prices, but trade stores often beat them on bare-tool deals when you already own batteries.
Cordless circular saws have finally caught up to corded power on most jobs, but the voltage question still trips people up. Do you need 36V, or is 18V genuinely enough for framing timber?
We've dug into the specs, tested cutting speed through common timber sizes, and compared what's actually available at Bunnings and trade stores across Australia.
Why Voltage Matters When Choosing a Cordless Circular Saw
Voltage isn't the whole story with any cordless circular saw, but it's a decent shorthand for how much sustained power you're getting.
Higher voltage generally means more torque under load, which matters when you're ripping through wet hardwood or a stack of LVL beams. But it also means heavier tools, pricier batteries, and sometimes overkill for jobs a smaller saw handles fine.
18V Systems Explained
18V is the most common cordless circular saw voltage in Australia, and for good reason. Brands like Makita, DeWalt, Milwaukee and Ryobi all build their broader tool ecosystems around 18V (or "20V Max" in DeWalt's marketing, which is actually the same 18V cell technology).
The big advantage is battery sharing. If you already own an 18V drill, impact driver or grinder, an 18V circular saw slots straight into your existing batteries and charger. No new investment beyond the bare tool.
Modern brushless 18V saws like the DeWalt DCS391 18V circular saw handle 90mm framing pine, treated pine decking, and most sheet goods without struggling. Where they start to labour is in continuous cuts through dense hardwood or thick structural timber.
20V Systems Explained
"20V" is largely a labelling quirk rather than a genuinely different voltage class. DeWalt and Ryobi both market their 18V-equivalent platforms as "20V Max," measuring peak voltage rather than nominal voltage.
In real terms, a 20V Max saw performs almost identically to a true 18V saw of similar build quality. Don't choose between "18V vs 20V" based on the number alone — look at battery amp-hours, brushless motor specs, and blade diameter instead.
36V and Dual-Battery Systems Explained
36V cordless circular saws (sometimes badged 36V, other times as dual 18V batteries wired in series) are built for jobs that would normally demand a corded saw or petrol saw.
Makita's 36V (2x18V) system, for example, powers a genuine 185mm blade with cutting depth and torque that rivals corded tools. These saws chew through 45mm hardwood decking boards, wet structural pine, and engineered beams without bogging down.
The trade-off is weight and cost. You're carrying two batteries instead of one, the saw itself is heavier, and a 36V-compatible battery pair can cost more than the bare tool itself if you're starting from scratch.
Real-World Cutting Tests: Power and Performance Compared
Numbers on a spec sheet only tell half the story. We ran comparable saws through the same cuts to see how they actually behave on site.
Cutting Speed Through Framing Timber
Cutting 90x45mm treated pine, a quality 18V brushless saw and a 36V saw performed almost identically — both cut cleanly in under two seconds with no motor strain.
The gap widened noticeably on 140x45mm hardwood and glue-laminated beams. Here, 36V saws maintained consistent RPM through the cut, while several 18V saws (particularly older brushed models) visibly slowed and needed a second pass to finish cleanly.
If your work is mostly standard pine framing, an 18V saw won't hold you back. If you're regularly cutting hardwood decking joists or LVL beams, the extra torque of a 36V saw saves real time across a full day.
Battery Life Under Load
How long does a cordless circular saw battery last on one charge?
It depends heavily on battery capacity and what you're cutting, but here's a rough guide from our testing:
- An 18V 5.0Ah battery powering a brushless saw through treated pine framing: roughly 150–200 cuts per charge on 90x45mm stock.
- The same battery through 140mm hardwood: closer to 60–80 cuts before needing a swap.
- A 36V (2x18V 5.0Ah) setup through hardwood decking: around 250–300 cuts, thanks to the combined capacity and more efficient torque delivery.
Buying a second battery is worth it regardless of voltage. A flat battery mid-cut on a job site is the most common complaint we hear from tradies about cordless saws.
Top Cordless Circular Saws Available in Australia
Best for Tradies
What is the best cordless circular saw for framing in Australia?
For daily trade use, the Makita DHS680Z 18V circular saw remains the benchmark. It's brushless, lightweight at around 3.3kg, and shares batteries with the rest of Makita's LXT range — which covers a huge chunk of trade tool kits already.
If you're regularly cutting hardwood or thick engineered timber, the Makita DHS900Z 36V circular saw with its 185mm blade and deeper cutting capacity is the better long-term investment, despite the higher upfront cost.
Best for DIY and Weekend Projects
For homeowners tackling decking, sheds, and the occasional framing job, the Ryobi R18CS7 18V One+ circular saw is a smart pick. It taps into Ryobi's enormous One+ battery ecosystem, which already powers everything from lawn mowers to blowers in a lot of Australian garages.
It won't out-cut a premium trade saw, but for weekend decking projects and general renovation work, it's more than capable — and the battery works across dozens of other Ryobi tools you probably already own.
Best Value for Money
The Ozito PXC 18V circular saw from Bunnings is the standout budget option. At under $100 for the bare tool, it's a genuinely usable saw for occasional DIY use, provided you don't expect trade-level durability or all-day battery performance.
For a step up in build quality without trade-tool pricing, Milwaukee's M18 range offers a solid middle ground between Ozito's budget pricing and Makita's premium positioning.
Battery Compatibility and Buying Into a Platform
Can I use 18V batteries in a 36V cordless circular saw?
Generally, no — not directly. True 36V saws (like Makita's 36V line) require two 18V batteries slotted into dedicated dual ports, wired to deliver combined voltage. You can't run one on a single 18V battery.
This is actually the smart part of Makita's design: your existing 18V batteries do double duty, working individually in smaller tools or paired up for the 36V saw. You're not buying an entirely separate battery format.
DeWalt's FlexVolt system works similarly, with batteries that automatically switch voltage depending on the tool they're inserted into.
The real lesson here: buy into a platform, not a single tool. Before choosing a saw, check what battery format your drill, grinder, or impact driver already uses. Staying within one ecosystem saves hundreds of dollars over a few years of tool purchases.
| Platform | Voltage | Battery Shared With | Typical Bare Tool Price |
|---|---|---|---|
| Makita LXT | 18V | Drills, grinders, blowers | $199–$249 |
| Makita LXT x2 | 36V | Larger LXT tools | $349–$429 |
| DeWalt 20V Max | 18V equivalent | Full DeWalt 20V range | $189–$259 |
| DeWalt FlexVolt | 54V/18V | FlexVolt mitre saws, blowers | $399–$499 |
| Ryobi One+ | 18V | Huge outdoor/indoor range | $99–$149 |
| Ozito PXC | 18V | Ozito budget range | $79–$99 |
Bunnings vs Trade Store Pricing and Availability
What cordless circular saw brands does Bunnings sell?
Bunnings stocks Ozito (exclusively), Ryobi, Makita, DeWalt, and Milwaukee across most stores, with online availability for the broader range. It's the easiest place to physically handle a saw before buying.
Where Bunnings tends to win is bundle deals — kits with a drill, saw, and two batteries often work out cheaper than buying tools separately.
Trade stores like Total Tools and Sydney Tools generally have better pricing on bare tools (saw only, no battery), which suits tradies already invested in a battery platform. They also tend to carry a wider Milwaukee and Makita range, including higher-end models not stocked at Bunnings.
Mitre 10 sits somewhere in between — solid Ryobi and DeWalt stock, occasional clearance pricing, but a smaller range overall than Bunnings' flagship stores.
Which Cordless Circular Saw Should You Buy?
Is 18V or 36V better for a cordless circular saw?
For most people, 18V is the right answer. It's lighter, cheaper, and shares batteries with the rest of your tool kit. Unless you're cutting hardwood or engineered timber daily, the extra torque of 36V goes unused.
Do I need a 36V saw or is 18V enough for framing timber?
Standard pine framing (90x45mm, 70x35mm) is comfortably handled by any decent 18V brushless saw. Only step up to 36V if hardwood, wet timber, or thick engineered beams are a regular part of your work.
Which cordless circular saw is best for decking and construction?
For treated pine decking, 18V is fine. For hardwood decking boards (spotted gum, blackbutt, merbau), a 36V saw like the Makita DHS900Z will save you time and reduce motor strain across a full deck build.
Frequently Asked Questions
What is the best circular saw brand overall in Australia? Makita and DeWalt lead on trade reliability and battery ecosystem size, with Milwaukee close behind. Ryobi is the best mainstream choice for DIYers already in the One+ system.
Are brushless motors worth paying extra for? Yes. Brushless motors run cooler, last longer, and deliver noticeably better battery efficiency than older brushed circular saws.
Can I put a bigger blade on my cordless circular saw for deeper cuts? No — blade diameter is fixed to the saw's design (typically 165mm for 18V saws, 185mm for many 36V saws). Buying the right size upfront matters.
The Bottom Line
An 18V cordless circular saw handles the vast majority of Australian framing, decking, and DIY work, and it's the smarter buy if you're already invested in a battery platform. Reach for 36V only if hardwood and engineered timber are a regular part of your cutting list — the extra torque and battery life are genuinely worth the higher price there. Whichever voltage you choose, buy into a brand ecosystem you already own tools from, and grab a spare battery before your first big job.
