Mattresses usually need replacing every 7 to 10 years which makes it an important long-term investment. While you can still pop into a store and have a thoughtful bounce on display models, that's only one way of buying a mattress today.

Take ride on the tube and you'll see loads of ads for online mattress companies, and though it may seem like a gamble to pick up a mattress without seeing it first, many of these company have policies where you can try the mattress for several months as a trial. 

Of course, before you get to actually buying the mattress, it's important to identify what you need. Here, we've gathered up all you need to know on choosing a mattress – from the types of mattresses, what to look for, and where to buy them.

Also check out our round up of the best sleep trackers and the best SAD lamps

Types of mattresses

Innerspring - The innerspring or coil mattress is the most common type you'll find. It's your traditional coil mattress and one of the more affordable options. Spring mattresses are also better at staying cool due to the space between the coils, which allows better airflow.

There are a few types of innerspring options to choose from:

  • Bonnell - This is the most traditional type of coil mattress, with springs that form an hour-glass shape. While this provides even support, you may experience motion transfer.
  • Continuous/open/cage sprung coil - These mattresses use a single wire throughout that's coiled in rows of S-shapes. It's usually cheaper than other types of mattresses but may struggle with providing proper long-term support.
  • Marshall/Pocket - These coils are wrapped separately – that is, the coils are not interconnected. Marshall or Pocket coils are often described in gauges. A higher gauge means  the springs are thinner and that the the mattress is softer. These are better for reduced motion transfer.
  • Offset - These coils are similar to Bonnell coils and have an hourglass shape, except either ends of the coils are flattened. This helps with support and are also less squeaky.
Innerspring mattress Innerspring Bonnell mattresses feature hourglass-shaped springs. Image: iStock.

Memory foam - You probably have a good idea of what memory foam is already. Its firm, yet spongy, and takes on the contours of your body when you lie down. It's great if you want to feel cushioned and simultaneously supported.

Memory foam mattresses are ideal for back sleepers and those who want minimal motion transfer, but these mattresses can get warm overnight.

Gel - This is similar to the memory foam, but has a cooling gel that's integrated. The density of memory foam mattresses can cause it to overheat during the night, which may disrupt some sleepers. Gel mattresses offer a cooler alternative, while still offering the comfort and support of a memory foam.

Innerspring Marshall Spring Mattress
Marshall or Pocket Spring mattress use individual coils instead of interconnected ones. Image: iStock.

Latex - Latex mattresses, like memory foam mattresses, offer cushioning and support. Latex mattresses are a bit bouncier, so you won't sink in the same way you would on memory foam. It also stays cooler overnight.

Latex Mattress
Latex mattresses are similar to memory foam but stay cooler. Image: iStock.

Hybrid - If you can't choose between spring and foam, hybrid mattresses offer the best of both worlds. Hybrid mattresses come with a spring base which is then layered with latex or memory foam on top. 

Pillowtop - These mattresses can be on the more expensive side as they consist of a thick foam or latex padding on top (or sometimes other materials like cotton or wool). These are better for those who prefer more cushioning.

Pillowtop mattress
Pillowtop mattresses come with a padded layer on top, but can be more expensive. Image: iStock.

Choosing a mattress by sleeping position

Your sleeping position should also play into how you choose a new mattress. If you sleep on your back, a memory foam is likely the best route forward as it can fit around your form to support your spine.

Side sleepers should opt for mattresses in the softer to medium range. This helps cushion your hips and shoulders while still supporting your spine if you change positions. 

Those who sleep on their stomachs would benefit from medium to firmer mattresses. If your mattress is too soft, you risk sinking too much and losing support.

This is where it can be useful to head into a mattress show room, even if you choose to buy online. Some mattress companies, like Nectar Sleep, will also allow you a trial period up to a year. 

Choosing a mattress by body weight

It's also worth keeping your weight in mind before choosing a mattress. This will affect the support and feel of the mattress (does it sink too much or not enough?) and cooling.

Most mattresses of medium firmness are made for an average weight of 180lbs. If you weigh less than this, you may find firmer mattresses uncomfortable because there isn't enough 'hug', which refers to how well you sink into the mattress, and how well it contours against your body. Those on the lighter side may prefer a softer mattress.

A medium mattress will likely be fine for those with an average weight (150 to 200 pounds), but you can opt for a softer mattress too if you want more hug.

Heavier sleepers (200 pounds or more) will benefit from a firmer mattress. This will offer better back support and also prevent any overheating caused by sinking. 

Where to buy a mattress online

You can buy a mattress online from loads of retailers. We've listed popular ones below: