Which is better for framing and deck work?

The DCS578 has more power and weighs less, so it handles long rips in thick stock with less strain. The DCS590B still cuts 2-9/16 in at 90° and is fine for most framing if you already own 20V batteries.

Do both saws use the same battery?

No. The DCS590B runs on DeWalt 20V MAX batteries. The DCS578 runs on 60V MAX FlexVolt batteries. FlexVolt packs also work in 20V tools, but 20V packs will not run the 60V saw.

Is the DCS578 worth the extra money?

At $184.99 at Walmart versus $167.00 at eBay as of November 4, 2026, the gap is about $18. You get more power, a lighter body and a blade in the box, so it is worth it if you are starting fresh on FlexVolt.

Which one comes with a blade?

The DCS578 includes a 24-tooth high-speed steel blade. The DCS590B is listed without a blade and in generic packaging, so budget for a 7-1/4 in blade.

Which is lighter to use overhead?

The DCS578 at 8.2 lb is about 1.6 lb lighter than the DCS590B at 9.85 lb. That matters on overhead cuts and long days.

Which has the better price history?

The DCS590B has moved between $105.00 and $190.00 since October 30, 2026, so it pays to watch for a dip. The DCS578 has held between $184.99 and $189.00 in the same window.

DEWALT 20V MAX XR Brushless Cordless 7-1/4 in. Circular Saw, Tool Only (DCS590B) vs DeWalt FlexVolt 60V Max Circular Saw DCS578

Buy the DCS590B if you already own DeWalt 20V MAX batteries and want the lower price: $167.00 at eBay as of November 4, 2026, versus $184.99 at Walmart for the DCS578. Buy the FlexVolt DCS578 if you want more power and a lighter tool, and you are willing to buy into the 60V battery line. The DCS590B has swung between $105.00 and $190.00 since October 30, 2026, so its price moves more than the DCS578's.

Today the DEWALT 20V MAX XR Brushless Cordless 7-1/4 in. Circular Saw, Tool Only (DCS590B) costs $17.99 less at its best price.

Ask our shopping agent

It checks today's price at every store, compares the alternatives and answers in about a minute.