I'm running a new circuit to my workshop for some power tools and I want to make sure I get the wire size right. I've seen 12 AWG and 10 AWG mentioned online, but I'm not sure which one I actually need for a 20-amp breaker. Should I just go bigger to be safe?
12 AWG is your wire, and it's not just a suggestion - the NEC tables literally peg it as the minimum for 20 amps. The reason people get confused is that bigger wire (10 AWG) will *also* work, which makes folks think "well maybe I should just go bigger to be safe." Thing is, you're already safe. 12 AWG handles 20 amps just fine, and oversizing gets expensive for no real benefit, plus it's bulkier to work with in your conduit.
The one thing that might trip you up: make sure your breaker is actually a 20-amp and not something else. I've seen workshops where someone ran what they thought was a new circuit only to find out the breaker was labeled different or there was already something tied into that same line. Double-check your panel before you start pulling wire. Also, if you're running a longer distance to your workshop (like more than 100 feet or so from the panel), voltage drop becomes a consideration, but for a typical setup you're fine with 12 AWG. Just make sure you're using the right insulation type for your install - THHN, NM cable, whatever your local code expects - and you're golden.
For a 20-amp circuit, 12 AWG is the correct choice and what the National Electrical Code requires - it's rated for exactly that amperage, so there's no need to oversize.
Going with 10 AWG won't hurt anything, but it's unnecessary unless you're running the wire an unusually long distance (like over 100 feet), in which case voltage drop becomes a consideration.
The key is matching the wire gauge to your breaker rating, not guessing high, since oversized wire costs more and doesn't provide any real benefit in a standard workshop setup.
You need 12 AWG for a standard 20-amp circuit - that's what the code calls for and it'll handle your tools just fine.
The thing most people don't mention is to check what's already in your workshop before you run new wire; if you've got older 14 AWG circuits still working on 15-amp breakers, you can see how the previous work was done and match the quality and installation method.
10 AWG won't hurt anything and some folks do it anyway, but you're paying extra for wire and conduit you don't really need, and it's stiffer to work with in tight spaces. Just stick with 12 AWG, use proper connectors, and run it clean.
Go with 12 AWG and you're golden - that's what the code specifies for 20 amps and it's plenty capable for workshop tools.
The real thing to watch out for that nobody mentions is the actual run length; if you're pulling wire more than 100 feet or so from your panel, voltage drop can become an issue and you might want to bump up to 10 AWG anyway just to keep your tools running at full power.
Make sure whatever you install gets protected by a proper 20-amp breaker, and don't mix wire gauges in the same circuit because that's a mess waiting to happen.
Most folks get hung up on the "bigger is safer" thing, but 12 AWG is genuinely the right call here - it's not undersized or cutting corners, it's literally what the code specifies for 20 amps! The one thing that actually matters beyond wire gauge is what that person mentioned about run length; if your workshop is super far from the panel, you might hit voltage drop issues and need to think about that, but for normal distances 12 AWG handles it perfectly!
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