Test method

How we test trimmers

The uses we look at and the tests we run on every beard trimmer and groomer: runtime, battery fade, charge time, noise, pulling and stubble evenness.

Trimmers reviews

Every trimmer we review is used at home for several weeks on a real beard or on the body, on the unit we bought or borrowed. We time the battery when new and again at the end, time a full charge, measure noise at 30 cm and, for beard trimmers, count how often the trimmer pulls on a thick, coarse beard. That last test matters most for Indian beards, which are often dense and wiry.

Not every test applies to every trimmer: body groomers skip the beard tests, and the corded, USB and rinse tests apply only where the product is sold with that feature. Each result in a review links back to the matching test on this page.

What we score

Beard styling
How well it shapes a defined beard at different lengths, including clean edges at the cheek, neck and moustache.
Stubble upkeep
How evenly it keeps short stubble level, and whether a coarse, dense beard needs extra passes.
Detailing, nose and ears
How easily the head or attachments handle edges, eyebrows and nose-ear hair without catching.
Body grooming
How comfortable and safe a body groomer is on chest, arms, legs and underarms, and how long a session takes.
Travel
How practical it is in a bag: size, runtime between charges and whether it charges from a shared phone cable.

The tests

  1. Runtime on a full charge

    Measured in min Higher is better

    We charge the trimmer fully and run it continuously until it cuts out, on a new unit. We repeat the run three times and report the typical figure next to the runtime the brand lists.

  2. Runtime at the end of testing

    Measured in min Higher is better

    After four to six weeks of regular trims, we time a full charge to cut-off again in the same way. Comparing it with the first figure shows how quickly the battery is fading. The week of the re-test is noted with each result.

  3. Charge time from empty

    Measured in h Lower is better

    From cut-off, we charge with the charger or cable supplied in the box and time how long it takes to reach a full charge.

  4. Noise at 30 cm

    Measured in dB Lower is better

    We measure the sound level 30 cm from the running trimmer, roughly where it sits from your ear while trimming, in a quiet room.

  5. Passes that pulled hair (of five)

    Measured in passes Lower is better

    A tester with a thick, coarse beard makes five passes through the denser areas such as the chin and under the jaw. We count how many passes pulled or snagged hair. Body groomers are not put through this test.

  6. Evenness of a 3 mm stubble cut

    We trim the beard at 3 mm using the dial or comb, photograph the result against a ruler and note any steps, missed hairs or patches, and how many passes it took to get level.

  7. Runs plugged in with a flat battery

    Only for trimmers listed for corded use: we run the battery flat, then use the trimmer plugged into the wall, as you would during a power cut. Pass means it ran without a drop in speed.

  8. Charges from a phone adaptor or power bank

    Only for trimmers with a USB port: we charge from a phone adaptor and a power bank, and from a laptop port where we can, using the same cable. Pass means it charged normally from them.

  9. Rinses under a tap

    Only for trimmers listed as washable or waterproof: we rinse the head under a tap after trims, and the body where the listing allows, then check for faults or rust over the test period. Others are kept dry and wiped.