18V vs 20V Max: Is DeWalt's 20V Actually More Powerful?
Updated 2026-09-29
Short answer
No. An 18V pack and a 20V Max pack are both five lithium-ion cells in series. Each cell is about 3.6V under load and about 4V fully charged with nothing connected, so the same pack is 18V nominal and 20V at rest. DeWalt and Craftsman print the resting number; Milwaukee, Makita, Ryobi, Bosch and the rest print the nominal one. DeWalt's own small print gives the nominal voltage as 18.
The cell math
Voltage on a cordless pack is set by how many cells are stacked in series. Lithium-ion cells sit around 3.6V nominal and peak around 4V fresh off the charger. Every label on the market comes from that:
| Cells in series | Nominal | Resting maximum | Sold as |
|---|---|---|---|
| 5 | 18V | 20V | 18V (Milwaukee M18, Makita LXT, Ryobi ONE+, Bosch, Ridgid); 20V Max (DeWalt, Craftsman V20) |
| 6 | 21.6V | 24V | Flex 24V |
| 10 | 36V | 40V | Makita 40V Max XGT; Metabo HPT 36V MultiVolt |
| 15 | 54V | 60V | DeWalt FlexVolt 60V Max |
What that means in this catalog
51 of the 74 tools here run on five-cell packs, which is to say they're the same voltage class whether the box says 18 or 20. The numbers you should compare between an M18 and a 20V Max drill are the ones on the spec sheet — torque, speed, weight — and the price of the batteries. The voltage section has the full breakdown.
Where voltage does change something is the step up to ten-cell tools. Higher voltage moves the same power at less current, which runs cooler, and that matters on saws and grinders. The DeWalt FlexVolt DCS578 Circular Saw is the FlexVolt case: a FlexVolt pack runs as 20V Max in a 20V tool and rewires itself to 60V Max in a FlexVolt one.
What actually differs between the platforms
Not voltage. The tool lineup, the pack technology at the top of each range, the charger, the warranty, and what the batteries cost on sale. Those decide which color you're still buying ten years from now. Every platform compared, and the M18 against 20V Max head-to-head.