Best Cordless Angle Grinders: Ryobi vs Kobalt vs Metabo Head to Head

Introduction

Cordless angle grinders have quietly become one of the most competitive tool categories, and three recent entries show just how wide the spread is. The Ryobi PBLAG01 18V Brushless Angle Grinder targets value buyers, the Kobalt 24V Brushless Angle Grinder leans on extra voltage for efficiency, and the Metabo WPB 18 LTX BL 11-125 Quick positions itself as a premium, made-in-Germany replacement for an 11 amp corded grinder.

We compared all three on measurable performance: speed under load, maximum power output, run time, vibration, and price as tested.

How We Evaluated These Grinders

Each grinder was tested under a consistent 200 watt load, roughly what a normal grinding job demands, to measure how much speed each tool holds under real work. We then loaded each grinder progressively until it stumbled or cut off to find maximum power output.

Run time was measured in minutes and total revolutions under load, which represents the actual amount of work done per charge. Vibration was measured with the same slightly worn discs on each tool. Finally, we scored overall performance as a function of the price each tool was tested at.

Ryobi PBLAG01 18V Brushless Angle Grinder

The Ryobi is the lowest-priced kit of the group at $199, and that kit includes the newer high performance 4 amp hour battery. It is worth noting that this grinder seems to want a larger battery: kitted with the 9 amp hour pack it was tested at $310, moving it from well under a Harbor Freight Hercules to decently over one. Ryobi has also announced new 21700 cell battery lines in 8 and 12 amp hour sizes, which could further help this tool.

Under a 200 watt load it spins at 7140 RPM, a figure most users would be happy with for material removal. With the included 4 amp hour battery, that drops to around 6450 RPM, the largest battery-related drop we have seen in this class. The 9 amp hour pack’s bulk hurts balance, and at 6.4 pounds it ties for the heaviest 4.5 to 5 inch grinder tested.

Max power reaches 620 watts with the 9 amp hour battery, essentially matching its TTI sibling exactly, including nearly identical RPM under load. The catch is efficiency: with the 4 amp hour battery it manages only 430 watts. Run time came in at 12.5 minutes before both the tool and the battery got too hot to function, with the head reaching 140 to 145 degrees in spots against a more typical 120 to 125. Vibration is genuinely good though, at 21 m/s² with a 4.5 inch disc and 25 with a 5 inch disc, the best of the TTI tools tested. As a value score per dollar it lands at 118.8, essentially matching its sibling.

Kobalt 24V Brushless Angle Grinder

The Kobalt has the lowest tool-only price of the day at $130, making it a sweet low-hanging fruit if you already own Kobalt batteries. Tested with the 4 amp hour ultimate output battery plus the newer 8 amp hour 21700 cell pack, it came to $316. The 24 volt platform adds two extra cells, which puts it on the back foot in weight at 6.7 pounds, the heaviest grinder setup tested.

Under a 200 watt load it makes 5950 RPM, the lowest in the category, so material removal under steady pressure is slower. But it is affected far less by increasing loads thanks to its torque, and maxes out at 640 watts, which is quite good. With the smaller 4 amp hour 21700 cell battery that drops to 490 watts. In corded terms it performs like roughly a nine and a half amp model, similar to the Ryobi.

Run time is where the Kobalt shines: 22.5 minutes total, which normalizes to about 18 minutes on comparable watt-hours, the second highest tested, while staying cool at 118 to 120 degrees. Vibration is around average at 29 m/s² with a 4.5 inch disc, dropping to 21 with a 5 inch disc. Its value score is a very good 134.3.

Metabo WPB 18 LTX BL 11-125 Quick

At $470 as tested, the new Metabo is the clear premium pick, and it backs the price with the strongest results in nearly every measurable category. Made in Germany, it is designed as an 11 amp cordless replacement for the brand’s popular corded grinders. Useful features include a rotating battery lock so you can orient the bulky battery away from yourself and your workpiece, an RPM dial for lower-speed attachments and polishing, easily removable dust filters, a genuinely comfortable paddle switch, a clutch for bind-up situations, and overheating management.

Performance is where it separates. Under a 200 watt load it makes 8150 RPM, the fastest grinder tested. Max power climbs to 770 watts before it cuts out, with 660 watts arriving before it even reaches the free speed of most other grinders. Harder pushing barely fazes it. It compares to roughly an 11.5 to 12 amp corded grinder, ahead of the other two.

Run time is 12.5 minutes on an 8 amp hour battery, but the tool stayed barely above body temperature at 112 degrees, and because it runs at much higher RPM throughout, the total work done per charge was the highest of the group. Vibration is exceptional: 9 m/s² with a 4.5 inch disc and 12 with a 5 inch disc, near or matching the records in both cases. Its price drags the value score to 111.2, but on raw performance it dominates at 633.7 total, head and shoulders above the field.

Overall Buying Advice

If you want the best pure performance and are willing to pay for it, the Metabo is hard to argue with: fastest under load, highest power, lowest vibration, coolest running, and the most work done per charge. If you already own Kobalt batteries, the $130 bare tool is a major win, delivering the better part of a half hour of run time as a package with very good efficiency. The Ryobi makes the most sense for buyers already invested in its battery platform, though it clearly prefers the larger battery packs.

Conclusion

Measured side by side, the hype around the made-in-Germany Metabo translates into real numbers, and it is currently the grinder to beat in this class. The Kobalt is the value efficiency pick, and the Ryobi is a capable entry point that rewards bigger batteries. Match the tool to the battery system you already own and the job you actually do, and all three can earn their place.