How to choose a hair straightener for your hair type

Plate width and heat control decide whether a straightener suits your hair. Most of the other claims on the box matter far less. A wide styler on a short bob is a common mismatch. It can’t get close enough to the face, so the pieces at the front never sit flat, however many passes you make.

Start with your hair type

How much hair you have matters, and so does how long it is. Thickness and coarseness get mixed up a lot. Thickness is how many hairs you have. Coarseness is how wide each strand is. Plenty of people have a lot of fine hair, which takes a while to get through but still needs gentle heat.

Roughly:

Fine or thin hair scorches easily. Keep the heat low and use a plate you can control.
Thick or coarse hair needs more heat and more passes, and wider plates that heat evenly across the surface save time.
Got a short cut or a fringe? Slim plates reach right up to the root and along the hairline.
Long hair past the shoulders is quicker with wide plates, since each pass covers more.

Curly hair adds one step. Work in small sections so the heat gets through each one evenly.

Match the plate width to your hair length and thickness

Straightener plates run from about 15mm wide up to 43mm. The middle of the range, around 24–26mm, is the usual pick and makes sense for shoulder-length hair. It’s narrow enough to twist through your hair for loose waves, which a wide plate does badly. Wide plates are heavier, too, and harder to angle near your face. On short layers they’re awkward.

At the slim end, 15mm plates get close to the roots on fringes and short cuts. A 43mm plate takes a wider strip of hair each time, so long or thick hair needs fewer passes from root to tip. If you’re working out the best hair straightener in New Zealand for your own hair, ghd’s NZ range lists each model by plate width and the hair type it suits. Its plates are ceramic, which spreads heat evenly. Titanium plates heat up faster and are a common pick for coarse hair. Check the plate material as well as the width.

Get the temperature right

Heat damage builds up slowly. Each pass at too high a temperature dries out the outer layer of the hair (the cuticle), and over a few weeks that shows up as frizz and split ends. Extra passes add to it. That’s another reason wide plates are kinder to long hair: you go over each section fewer times.

Use the lowest temperature that gets a section straight in one or two passes. On fine or coloured hair, start somewhere around 150–170°C. Only turn it up if you find yourself going over the same piece again and again. Thick and coarse hair usually needs 190°C or more.

Some straighteners run at one fixed temperature. ghd’s are set to 185°C. Most others have a dial or a digital display, so you can drop the heat for fine hair. A fixed setting is simpler if you’d rather not think about it. A dial makes more sense when your hair changes a lot, after fresh colour or a big chop, or when two people with very different hair share one straightener.

Straighten only when your hair is completely dry, and put a heat protectant on first. Hot plates on damp hair heat the water inside each strand. That does far more harm than a few extra degrees.

Safety checks for Kiwi buyers

Don’t buy a straightener without automatic shut-off. It turns the plates off after a set time without use. On a rushed school morning, you can be halfway down the road before you wonder whether you unplugged it.

Cheap overseas listings carry a voltage risk. New Zealand runs on 230V with the angled plug we share with Australia, while some straighteners made for the US market run on 110–120V only. A travel adaptor changes the plug shape. It doesn’t convert the voltage, so a single-voltage model can overheat or stop working. Buy from an NZ stockist and the problem doesn’t come up.

If you’re stuck between two sizes

Choose for the length your hair usually is between cuts, rather than the week after the hairdresser. Want waves as well as sleek straight hair? Go for a standard plate over a wide one. The narrower plate is much easier to twist.

A slim plate can come later as a second tool, if you’re growing out a fringe and only need to tidy the front.