How Many Watts Does a Clothes Iron Use? Monthly kWh and Compared With a Hair Dryer

How many watts does an iron use?

• 1,500 W, averaging 750 Wh per hour of use, according to the table from Argentina’s electricity regulator (ENRE).
• 1,000 to 1,800 W, according to the U.S. Department of Energy table reproduced by Virginia Tech.
• 1,500 W as well in the table of typical wattages in the guide from IDAE, Spain’s energy agency (2010 edition).

Your iron’s watts are on its rating plate, a label or embossed lettering on the handle or base, next to the volts.

Why does it use half its watts?

In the ENRE table the iron is rated at 1,500 W, but in an hour it uses 750 Wh, half. That’s the thermostat: the element runs at full power until the soleplate is hot, switches off, and comes back on when it cools. That’s why many irons have a small light that goes on and off while you iron.

A hair dryer is different: in the same table it’s rated at 2,000 W and uses 2,000 Wh in an hour, because it heats nonstop while it’s on.

How much does it use per month?

With the ENRE figure, 750 Wh per hour of use:

• Half an hour a day for a month: 750 × 0.5 × 30 = 11,250 Wh, about 11.3 kWh.
• One 2-hour session a week: 750 × 2 = 1,500 Wh each time; with 4 sessions a month, 6 kWh.

That’s what the electricity usage calculator gives with the iron at half an hour a day. For comparison, a fridge-freezer uses about 65 kWh a month in the same table: almost six times more.

Iron, hair dryer or tumble dryer: which uses more?

In the ENRE table, per hour of use, a hair straightener uses 40 Wh; a spin dryer, 380 Wh; a heated tumble dryer, 950 Wh; and a hair dryer, 2,000 Wh. The U.S. Department of Energy table gives the hair dryer 1,200 to 1,875 W, and the IDAE guide, 1,200 W.

Per hour, the hair dryer uses the most, but it usually runs for less time: 12 minutes a day is 2,000 × 0.2 × 30 = 12 kWh a month.

Worked example: iron and hair dryer in one home

1. The iron, half an hour a day: 750 × 0.5 × 30 = 11.3 kWh a month.
2. The hair dryer, 12 minutes a day: 2,000 × 0.2 × 30 = 12 kWh a month.
3. Together: 11.3 + 12 = 23.3 kWh a month.
4. If the ironing becomes one 2-hour session a week: 6 + 12 = 18 kWh a month.

The minutes are just an example: enter yours in the calculator. To see what you pay, multiply the kWh by the price per kWh on your bill.

How to use less when ironing

• Iron a big batch at once, to make use of the iron already being hot. This is advice from the IDAE guide.
• Don’t leave it on if you’re going to stop, also according to IDAE.
• The same guide says irons with a compact steam station (a separate steam tank) save up to 46% compared with conventional steam irons. That figure is from 2010.

If you plug it into a power strip, generator or inverter

While it heats, the iron draws its full wattage. A 1,500 W iron is 1,500 ÷ 120 = 12.5 A in a 120 V home, and 1,500 ÷ 230 = 6.5 A in a 230 V home. If you also plug the hair dryer into the same strip, that adds up to 3,500 W: check it first with the power strip calculator.

The same goes for a generator or inverter: it has to supply the iron’s 1,500 W plus whatever else is running. An iron has no start-up surge like a fridge, because it has no motor. We do the full math in what size generator you need. On a battery, half an hour of ironing takes about 375 Wh, plus what the inverter loses.

Common mistakes

• Thinking it draws its 1,500 W the whole time. The thermostat switches it on and off: in the ENRE table it uses 750 Wh per hour.
• Leaving it on while you do something else. It keeps using power to stay hot; IDAE advises switching it off if you interrupt the task.
• Plugging it into the same power strip as the hair dryer or toaster. Together they can exceed what the strip can handle.

When to call an electrician or a technician

If the breaker trips when you plug in the iron, or the outlet gets hot or smells burnt, unplug it and call an electrician. If the cord is frayed or the iron gives you a shock, don’t use it or fix it yourself: take it to a technician or replace it.