How to choose a heated mattress pad

1. Measure before you shop

This is the step people skip and it is the one that generates returns. Every pad here claims to fit up to 18 inches. Measure the mattress you actually have, from the top surface down to the underside, and include anything already on it.

A pad that is fractionally too small does not simply feel tight. The elastic works against the seams every time somebody moves, the pad creeps toward the middle of the bed, and you end up with the heating element bunched somewhere it was not designed to bunch. That is both a comfort problem and, per every manual in our set, the condition you are told to avoid.

2. Dual zone or single

Dual control starts at queen across every brand we checked. Serta and Valthie both state it explicitly; the others imply it. Below queen you get one controller and there is no option.

It matters more on a pad than on a blanket because the heat is directly underneath both of you and conducts sideways through the mattress core. Detail on dual control pads.

3. The auto-off ceiling, in both directions

Nine hours or twelve, and it is genuinely not obvious which is better.

• Twelve hours suits a long winter night and a bed you want warm when the alarm goes. Bedsure, Sunbeam, Serta and Valthie all reach it.
• Nine hours is Sealy's ceiling and it is a deliberate choice: the bed is warm when you get in and definitely off before the middle of the day, with no reliance on you remembering.
• Hour-by-hour selection is the most flexible arrangement. Sunbeam and Serta both let you set the shut-off in single-hour increments up to twelve.

4. Waterproofing, if the household calls for it

Three different claims that are routinely confused: waterproof means a barrier layer, water resistant means the surface sheds a splash, and protector is a coverage claim. Only Bedsure's cotton-top pad names a barrier material. Full breakdown on waterproof heated mattress pads.

The tiebreaker: does it publish a wattage

One brand in six does. Bedsure publishes dual 100 W controllers on both its pads, which makes an eight-hour night about 29 cents with both zones on. Sunbeam, Sealy, Serta and Valthie publish nothing you could compute from.

We would not buy a worse-fitting pad for a published number. Fit comes first and it is not close. But between two pads that both fit, both zone correctly and both shut off when you want, the one that tells you what it draws is the better-documented product, and that is a reasonable thing to reward.

Two things that are not worth comparing

Every pad here is ETL certified or states overheat protection, and every one is machine washable with the controllers detached. Neither distinguishes anything.

One universal instruction is worth repeating because it appears in capitals on several of these listings and is still routinely ignored: do not leave the controller covered while the pad is in use. It is the part that senses temperature. Under a duvet it cannot do its job.

And the question before all of them

Is a pad the right product at all? If the problem you are solving is getting into a cold bed, yes, and it is the better answer than a blanket. If the problem is staying warm on a sofa, a heated throw is the right product. If it is being cold in bed once you are already in it, a blanket sits above you and does that job more directly. The full comparison is on blanket versus pad.