Compact vs. Full-Size Impact Driver: Which Size Fits a Homeowner?
Impact drivers come in two broad sizes. The 12V "subcompact" class is small and light. The 18V/20V class has more torque for big fasteners. To show the gap with real numbers, here are two kits from the same brand. We read both spec lists on Milwaukee's own pages tonight. We haven't tested either tool hands-on, so there are no ratings here.
| Kit | Maker-listed specs | In the box (per maker) | Price |
|---|---|---|---|
| Milwaukee M12 FUEL 1/4" Hex Impact Driver Kit (3453-22) | 12V; brushless; up to 1,500 in-lbs torque; up to 3,600 RPM in mode 3; 4 drive modes including a self-tapping screw mode; 5" long; tool weight listed at 2 lbs | Two M12 CP2.0 batteries, charger, belt clip, contractor bag | Check current price |
| Milwaukee M18 FUEL 1/4" Hex Impact Driver Kit (2953-22) | 18V; brushless; 2,000 in-lbs torque; 3,900 RPM; 4 drive modes; 4.47" long; 3.8 lbs with battery | Two M18 XC5.0 batteries, M18/M12 charger, hard case, belt clip | Check current price |
One caution when you compare the weights: Milwaukee gives the M12 figure without saying it includes a battery, while the M18 figure is stated "with battery." Don't read them as a like-for-like comparison.
Which size makes sense
Go compact (12V) if most of your jobs are hanging shelves, assembling furniture, putting up curtain rods, or working overhead and inside cabinets. A light tool is easier to hold up for a long time, and 1,500 in-lbs is plenty for ordinary wood screws.
Go full-size (18V/20V) if you plan to build a deck or fence, drive long structural screws or lag bolts, or you already own batteries from that platform. The higher torque and the bigger 5.0Ah packs in this kit help with long runs of large fasteners.
Whichever you pick, stay on the battery platform you already own. Batteries generally don't swap between brands. See 12V vs. 18V/20V and drill vs. impact driver for the background.
Sources: https://www.milwaukeetool.com/products/details/m12-fuel-1-4-hex-impact-driver-kit/3453-22, https://www.milwaukeetool.com/products/details/m18-fuel-1-4-in-hex-impact-driver-kit/2953-22. Specs checked on the manufacturer pages on Oct 21, 2026.