All guides

Each guide answers one buying question and shows the figures behind the answer.

3 guides

White hair straightener lying open, showing two narrow heated plates, control buttons and a cord

How to choose

Choosing a hair dryer or straightener: the plug, the watts, the dial

Three things decide a styling tool: the immersion protection block on the plug, the wattage on the plate, and whether the heat dial reads in numbers.

Updated 11/3/2026 · 8 min

Photo: Lombroso · CC BY-SA 4.0 · Wikimedia Commons

Gold and black hair straightener lying open with a small temperature display and control buttons

Budget and prices

What a hair dryer actually costs you per use

Divide the price by the sessions you will get from it, add the electricity from the rated wattage, and a $400 dryer and a $120 one stop looking similar.

Updated 11/3/2026 · 8 min

Photo: Lombroso · CC BY-SA 4.0 · Wikimedia Commons

A hand drawing a black flat-plate straightener down a long section of straight brown hair

Reactions and irritation

Heat, fumes and irritation: the three risks that have published numbers

Formaldehyde released from heated smoothing products, exposure limits in parts per million, and the plug device that exists because dryers end up in water.

Updated 11/3/2026 · 8 min

Photo: Leomedia · CC0 · Wikimedia Commons