So, you want to understand what dipped headlights are and when they are needed. You’ve come to right place – let this Carwow guide shine a light for you.

Dipped headlights are the ones you’ll likely use most often. They’re named as such because the beam faces down towards the road. They are brighter than sidelights and daytime-running lights, but less bright than full beam headlights.

Because dipped headlights point down, they don’t illuminate the road ahead as well as full-beam headlights. But that also means they don’t shine in the eyes of road users coming towards you on the other side of the road.

When should you be using dipped headlights, though? And when should you use full-beam? This guide explains.

According to the Highway Code, you must use headlights at night and “when visibility is seriously reduced”. This is generally considered when visibility is restricted to 100 metres or less and includes driving in fog and heavy rain.

On top of that, it suggests to “use dipped headlights, or dim-dip if fitted, at night in built-up areas and in dull daytime weather, to ensure that you can be seen.” It also states you must not “use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders.”

Essentially, this means using dipped headlights rather than full beams when oncoming traffic is nearing or if you’re close to other road users ahead. You should also keep them dipped while overtaking.

In most cars, turning on your dipped headlights will be as simple as twisting a knob or a switch.

You’ll see a dome-like shape with lines directing downwards on the stalk to indicate low-beam headlights are on. This should also show a matching green or yellow symbol within your instrument cluster.

If this shows as blue with the lines pointing straight on, this means your high beam headlights are on. Switching these to dipped headlights will typically require you to pull the stalk on the left towards you.

Many modern cars have automatic lighting and turn on the headlights for you in low light conditions. Some have more sophisticated adaptive lights which adjust the headlight beam to suit different roads and conditions, avoiding the need for the driver to switch between high-beam and dipped headlights.

In some modern cars with very few buttons and most functions controlled through a touchscreen, you may have to use an on-screen menu to adjust the headlight settings.

Main-beam (or high-beam) headlights are designed to improve visibility well ahead of the car at night by projecting light further down the road. This is ideal if you’re driving on a country road with no street lighting, for example.

However, main-beam headlights can dazzle other road users making it harder for them to focus on objects up ahead and to judge speed and distance. Because of this, you should switch to dipped headlights when oncoming traffic is approaching or if you’re following another car.

You should use dipped headlights in the daytime when visibility is reduced. Heavy rain and fog both make it harder to see, so switching on your dipped headlights is a good idea. Turning on your dipped headlights and taillights makes it easier for other road users to spot your car.

Switch on your dipped headlights whenever visibility is reduced to 100 metres or less.

In the UK, dipped headlights are white or may have a yellow tint. The lights must carry an E-mark or a British Standard mark.

If you’re driving with a headlight out, police can pull you over and hand out a fixed penalty notice of £100.

If you have a dipped headlight out, it’s best to avoid driving until you can replace the unit. You can still be pulled over and using main beams will dazzle other road users.

Fog lights are separate from dipped headlights. They’re designed to illuminate the road below the fog with a short but high beam, as well as making you more visible to other road users.