How much does an electric blanket cost to run in NZ?

Very little - about $27 a year used the normal way, which is half an hour to an hour before bed. Even left on for a full eight-hour night, every night, it comes to roughly $106 a year. It is one of the cheapest heating decisions available in a New Zealand house.

Is it cheaper to use an electric blanket or heat the bedroom?

The blanket, by a wide margin. Running it all night costs about $106 a year against roughly $1,019 to run a heat pump in the bedroom overnight - and the heat pump is the efficient option. A plug-in heater overnight is several times that again. The reason is simple: a blanket heats a bed, and a heater heats a room, and the room is much bigger than the bed.

Can you leave an electric blanket on all night?

Only if it is designed for it - many are rated for pre-warming only and should be switched off when you get in. Check the label rather than assuming, because that instruction is about the element and the thermostat, not about the power bill. Modern blankets with a low-wattage all-night setting are fine to run through; older ones frequently are not.

When should an electric blanket be replaced?

Consumer NZ and Fire and Emergency both point at roughly ten years, and sooner if anything is wrong. Check it before every winter: unfold it flat and look for scorch marks, exposed or kinked element wire, frayed cord and a damaged controller. If any of those are present, replace it - this is the one appliance on the whole site where the safety question genuinely outweighs the running cost, because the running cost is negligible and the failure mode is a fire in a bed.

Running cost

What an electric blanket costs to run in NZ (and why it wins)

By Jason Webb· Published 6 August 2026· Updated 6 August 2026· 6 min read

Most pages on this site exist to tell you something costs more than you thought. This one is the opposite. An electric blanket costs about $27 a year used normally, and even left on all night, every night, it is around $106.

At 100 watts it draws about the same as a laptop, and it is doing something no heater can: warming a person directly rather than warming the several thousand litres of air around them.

The comparison that matters

The right question is not "what does a blanket cost" but "what is the cheapest way to be warm in bed on a cold night". Every one of these achieves that:

Annual cost of staying warm overnight, five ways, at 36.3c/kWh
Method	What it is	Per year
Electric blanket, 30 min before bed	100W, used to pre-warm the bed	$7
Electric blanket, on all night	100W for 8 hours	$106
Heat pump heating the bedroom	2.5 kW output, 8 hours overnight	$1,019
Oil column heater in the bedroom	2,400W for 8 hours	$2,545
Fan heater in the bedroom	2,000W for 8 hours	$2,121

A heat pump is the efficient way to heat a room, and it still costs roughly 10 times what the blanket does for the same night's comfort. The plug-in heaters are worse again, for the reasons set out on our oil column heater page. If you take one thing from this table: heating the bed instead of the bedroom is among the highest-return swaps in the house.

Why bedroom heating is the wrong instinct

New Zealand bedrooms are frequently the coldest rooms in the house - often unheated, often on an outside wall, often the room where condensation shows up first. The natural response is to put a heater in there, and it is an expensive response for two reasons.

First, you are asleep. Heating a room for eight hours to benefit someone who is unconscious under a duvet for all of them is buying comfort nobody experiences. Second, a bedroom heater runs against the coldest part of the day and, in most houses, the least insulated room - so it runs almost continuously.

There is also a health argument that cuts the other way and is worth knowing: the World Health Organization and New Zealand's own Healthy Homes guidance both point at bedrooms being too cold, not too warm, particularly for the very young and the elderly. A blanket addresses the person; it does not address a room at 8°C with condensation running down the window. If that describes your bedroom, the answer is insulation and ventilation rather than either a blanket or a heater - our guide on insulation versus heating works through which to do first.

The part that actually matters: age

Because the running cost is negligible, the only real decision an electric blanket presents is whether yours is safe. This is the one appliance on this site where that is the headline.

Consumer NZ and Fire and Emergency New Zealand both put the replacement point at around ten years. Before each winter, unfold the blanket flat on the bed and check for:

Scorch marks or discoloured patches - these indicate a hot spot where the element has been stressed.
Element wire that is visible, kinked or bunched. Folding a blanket for storage rather than rolling it is the usual cause.
A frayed cord or a cracked controller, or a controller that runs warm.
Damp. Never use a blanket that has been wet, and never put one on a bed that has an unaired mattress under it.

If any of those are present, replace it. A new blanket costs less than a winter of running a bedroom heater, and the failure mode you are avoiding is a fire in a bed with somebody in it.

Getting the most out of it

Pre-warm rather than run through. Half an hour before bed puts the heat where you want it; the duvet then holds it. That is the $7-a-year row.
Check whether yours is rated for all-night use before leaving it on - this is a safety instruction, not a cost one.
Roll it for storage, do not fold it. Folds are where elements break.
Pair it with a warmer room, not a warm room. The blanket handles the bed; ventilation and insulation handle the condensation.

To compare it against your own heating setup at your own rate, open the calculator, or see where it sits among everything else in the full appliance table - near the very bottom, which is exactly the point.