Cordless drill buying guide: voltage, torque and brushless motors

A cordless drill is usually the first power tool people buy, and for good reason: it drills holes, drives screws and assembles furniture without hunting for a socket. Choosing one means understanding a handful of numbers — voltage, torque, battery capacity — and one big decision about battery platforms. This guide explains each of them, and what to check before you buy.

Drill driver, combi drill or impact driver?

Drill driver

Drills holes in wood, metal and plastic and drives screws. It has an adjustable clutch that slips at a set torque so you do not over-tighten screws. Drill drivers are usually lighter and more compact than combi drills.

Combi drill

A drill driver with an added hammer action for drilling into brick, block and masonry. If you will put up shelves on masonry walls, this is the type most homes need. The hammer setting is switched off for wood and screws.

Impact driver

Designed for driving screws and bolts, particularly long ones, using rotational impacts. It has a hex chuck for driver bits and no clutch. Many people buy one as a second tool alongside a drill; it is not a substitute for drilling holes in masonry.

For very hard masonry or concrete, a dedicated SDS drill is a better tool than a combi drill.

Voltage and battery platforms

In the UK, cordless tools are usually sold as 12 V or 18 V platforms (some brands call 18 V "20 V max"). Higher-voltage platforms tend to deliver more power for demanding jobs, while 12 V tools are smaller and lighter for furniture, cabinets and work in tight spaces.

The platform is the bigger decision. Batteries usually only fit tools from the same brand and voltage range, and they are often a large part of the cost of a kit. If you already own batteries from one brand, buying "body only" tools on that platform can be much cheaper. Before you commit, check how many tools the platform offers and whether the brand has a history of keeping batteries compatible.

Torque, speed and clutch

Torque is turning force, quoted in newton metres (Nm). Higher torque helps with large drill bits and long screws. Manufacturers sometimes quote torque in different ways (for example, hard and soft joint figures), so compare figures from the same brand or the same measurement.

Speed is quoted in revolutions per minute (rpm), usually across two gears: a low gear for driving screws with more control and torque, and a high gear for drilling.

Clutch settings let you choose the torque at which the drill stops turning a screw. More settings give finer control, useful for small screws and soft materials.

Blows per minute (bpm) applies to the hammer function on combi drills.

Brushless or brushed motors

Brushless motors are electronically controlled rather than using physical brushes. They are generally more efficient, which can mean longer runtime from the same battery, and they need less maintenance. They usually cost more. For occasional DIY, a brushed motor can be perfectly adequate; for regular use, brushless is often worth considering.

Batteries, chargers and kits

Battery capacity is quoted in amp-hours (Ah). A higher Ah battery runs longer but is heavier. Kits vary widely between retailers: one, two or no batteries; a standard or fast charger; a case or bag; and sometimes a set of bits. When comparing prices, make sure you are comparing the same kit contents.

Chuck, weight and ergonomics

Most cordless drills have a 10 mm or 13 mm keyless chuck; 13 mm accepts larger bits. Weight, balance and grip size matter if you work overhead or for long periods. An LED work light, a belt clip and a battery charge indicator are useful extras.

Key specs explained

Questions to ask before you buy

1. Will I drill into masonry, or only wood, metal and plastic?
2. Do I already own batteries for a brand, and does this tool use the same platform?
3. How many batteries are included, and what capacity are they?
4. Is the charger a standard or fast charger?
5. Is the price for a full kit or body only?
6. What warranty applies, and do I need to register the tool to get it?

Frequently asked questions

Do I need a combi drill?

If you plan to drill into brick or block walls, yes — a drill driver has no hammer action. For furniture assembly and woodwork alone, a drill driver is lighter and often cheaper.

Is a higher torque figure always better?

More torque helps with large bits and long screws, but a very powerful drill can be heavier and harder to control for small jobs. Match the torque to the work you do, and compare figures measured the same way.

What does "body only" mean?

The tool is sold without a battery or charger. It is good value if you already have compatible batteries from the same brand and voltage range.

Can I use batteries from another brand?

Generally not. Battery connections are specific to each brand's platform. Unofficial adapters exist, but using them may affect your warranty, so check the manufacturer's guidance.

Prices & links

HotWhatHow compares live prices from retailers as they are connected to the site. When offers are available, we rank them by the total landed price — the item price plus standard delivery — and show when each price was last checked. Kits vary between retailers, so check what each offer includes. Some retailer links are affiliate links; we may earn a commission, which never changes which offer we label as the cheapest. This guide is based on manufacturer specifications and general product information, not on our own use of the products. Always follow the manufacturer's safety instructions and use appropriate protective equipment.