Product Comparison: DEWALT DCD991B vs DEWALT DCD791B

Advertiser Disclosure

This site is a free online resource that strives to offer helpful content and comparison features to its visitors. Please be advised that the operator of this site accepts advertising compensation from certain companies that appear on the site, and such compensation impacts the location and order in which the companies (and/or their products) are presented, and in some cases may also impact the scoring that is assigned to them. The scoring that appears on this site is determined by the site operator in its sole discretion, and should NOT be relied upon for accuracy purposes. In fact, Company/product listings on this page DO NOT imply endorsement by the site operator. Except as expressly set forth in our Terms of Use, all representations and warranties regarding the information presented on this page are disclaimed. The information which appears on this site is subject to change at any time. More info

General Specifications
About the Product
The 20V MAX Drill/Driver (DCD991) features a powerful brushless motor that supplies 820 Units Watts Out (UWO) for a faster application speed. Featuring durable nitro-carburized metal ratcheting chucks and comfortable handle grips, these tools are GUARANTEED TOUGH for durability on the jobsite and include coated and sealed switches that help to resist moisture and dust contamination.
The DCD791B 20V MAX* XR® Li-Ion Compact Brushless Drill/Driver is lightweight and compact for working in tight spaces for long periods of time. High-speed transmission delivers 2 speed variations allowing users to choose the level of performance needed for various applications. Comfort grip adds balance and control.
Key Specs
820 watts
460 watts
885 in-lbs
Chuck Capacity
Rotation Speed
0-450 / 0-1300 / 0-2000 rpm
0-550 / 0-2000 rpm
What customers say about "Key Specs"
DEWALT DCD991B 20V MAX XR Lithium Ion Brushless 3-Speed Drill
  • The only problem is that this thing is so much more powerful than my previous battery-powered drill that on the low speed high-torque settings it will twist out of your hands trying to break loose a stubborn bolt if you have the tension set too high. Amazing. Serious oomph.
  • Very powerful cordless tool. FYI - Lowest speed highly recommended when changing bits, skin gets hot fast in high speed.
  • The power and build quality of these is amazing, the chuck seems to be offer more grip than most drills and the quickly adjustable (and removable) grip is great. Three speed gearbox is awesome and it's made a productive upgrade from my previous Dewalt drills.
  • Having three usable speeds with the gearing provided by DeWalt makes a tremendous difference in performance. I use the middle speed range with the Hole Pro Blue Boar 4 to 6 inch Mega TCT hole cutters to cut through 1-inch or thicker subflooring and it works great.
  • There's is so much power with this thing it drilled through 2x4 like butter.
DEWALT DCD791B 20V MAX XR Li-Ion Brushless Compact Drill
  • I love all DeWalt products and this drill too. It’s powerful, compact and 2 speeds to choose from
  • It gets the job done right. This newer model is ergonomic, well designed, strong motor and durable. One of the best power tool in the market.
  • The chuck is so much better , it holds bits TIGHT! The brushless motor has tons of power, hole saws in steel go through like a boss.
  • I love all DeWalt products and this drill too. It’s powerful, compact and 2 speeds to choose from
  • The old one is bulkier, larger, less powerful, and slower. This new DeWalt DCD791BR is the "big brother" to this size class of drills. Modern, strong, high torque, and bright light.
Size & Weight
9 in.
8.3 in.
8 in.
6.9 in.
4 in.
3 in.
4 lbs.
3.4 lbs.
What customers say about "Size & Weight"
DEWALT DCD991B 20V MAX XR Lithium Ion Brushless 3-Speed Drill
  • Very happy light weight drill and strong meets all my needs
  • I got this drill to replace one which had dead, unreplaceable batteries. It drills well and is a good weight for the power. I like the light.
  • Fantastic drill; long battery life and very compact for how much power it has.
  • This is a very light drill even with the 5 AH battery pack attached.
  • This is an excellent drill. It is light, powerful and easy to use.
DEWALT DCD791B 20V MAX XR Li-Ion Brushless Compact Drill
  • Compact, well designed , and LED light has three different settings
  • Great drill. Light weight & plenty of power.
  • Have always liked the weight and compact size on Dewalts entry models. For me, the compactness and weight exceed the benefit of more features, more aluminum housing and fancier looks.
  • perfect size/weight for the jobs that you'll be working above your head or holding your arm outstretched for long periods of time, so your arms don't get tired.
  • Why this model. Wanted the all steel chuck, do NOT want hammer function. Compact size.
Chuck Type
Cutting Cap. in Wood
4 in.
2 in.
Cutting Cap. in Steel
1.375 in.
1.375 in.
Torque Levels
Belt Hook
Lock-On Button
Rubber-Coated Handle
Battery Type
Ergonomic handle, 3-Mode LED provides lighting in dark work environments up to 20 times brighter than previous model, LED light with 20-second trigger release delay, DEWALT brushless motor, 3-speed, XR Li-Ion batteries with fuel gauge provide 33% more capacity
High-speed transmission delivers 2 speeds, LED light with 20-second trigger release delay, 3-Mode LED provides lighting in dark work environments up to 20 times brighter than previous model, Ergonomic handle, Compact, lightweight design fits into tight areas, DEWALT brushless motor
What customers say about "Features"
DEWALT DCD991B 20V MAX XR Lithium Ion Brushless 3-Speed Drill
  • I neglected to dial down the torque setting when driving a T-25 fastner, and the drill turned the bit into a spiral "barber pole".
  • The clutch functions different, and although I have seen no mention of it, I really like it. When the torque has been reached, instead of spinning on the clutch and impacting the fastener, it cuts the power and just stops.
  • Dam good drill. I got the non hammer one I'm not looking to drill concrete but this thing has some torque. And the light on this with it's 20 min stay on time is an amazing feature.
  • I liked this drills power, however the clutch (torque adjustment) collar was horribly unreliable when trying to use it as a screw driver.
  • Lots of torque. Unfortunately cannot adjust the torque well with the numbered ring.
DEWALT DCD791B 20V MAX XR Li-Ion Brushless Compact Drill
  • The LED light with timer is very handy too. Use the 4Ah batteries and you have powerhouse of a drill.
  • It also has adjustable torque settings for driving screws and the ratcheting chuck is a great improvement over the older Dewalt chucks.
  • Upgraded my 12 year old NiCad 18v to this and am very impressed. FAR more torque and probably 4x the RPM's and even more ergonomic than the older version. All steel chuck is really nice until you accidentally hit it at full speed and burn your hand so be careful there.
  • This has been my favorite Dewalt drill to date, mainly due to the led light. The chuck has yet to slip and still performs as new.
  • I'm glad DeWalt moved the LED to the base to broadcast light where the drill bit tip is being used.
Warranty / Certifications
Manufacturer Warranty
3 year(s)
3 year(s)
CSA Group, NOM
CSA Group, NOM
Other Information

Other reviews