How to buy a mattress: sizes, firmness, and what to test on the floor
By The LQ Furniture floor team ·
Buying a mattress comes down to three decisions: what size the room and the sleepers need, what firmness matches how you sleep, and whether the thing actually feels right after ten minutes lying on it in your normal position. Everything else is detail. The ten minutes is the part people skip, and it is the part that decides it.
Mattress sizes, and the room they need
| Size | Dimensions | Smallest room that works |
|---|---|---|
| Twin | 38 x 75 in | 7 x 10 ft |
| Twin XL | 38 x 80 in | 7 x 10 ft |
| Full | 54 x 75 in | 10 x 10 ft |
| Queen | 60 x 80 in | 10 x 11 ft |
| King | 76 x 80 in | 12 x 12 ft |
| California King | 72 x 84 in | 12 x 12 ft |
A queen is the most common choice for two adults and fits most bedrooms. A king gives each sleeper the same width as a twin, which is the real argument for it. A California King is four inches narrower and four inches longer than a standard king, so it suits a tall sleeper rather than a wide room, and it needs its own frame and sheets.
Before you settle on a size, measure the room and leave walking space: about 24 to 30 inches on the sides you get in and out of. Then measure the bedroom doorway, because a king mattress and its foundation still have to get down the hall.
Firmness follows how you sleep
Firmness is not a quality rating. It is a fit, and the fit is set mostly by your sleeping position and your weight.
- Side sleepers: softer to medium, so the shoulder and hip can sink and the spine stays straight
- Back sleepers: medium to medium-firm, enough support to keep the lower back from sagging
- Stomach sleepers: firmer, since a soft mattress lets the hips drop and bends the lower back
- Two people, different positions: medium-firm is the usual meeting point, or an adjustable base with a split configuration
Heavier sleepers generally want a firmer feel than the chart suggests, because they compress a mattress more. Lighter sleepers often want softer for the same reason. If you and your partner disagree, buy for the side sleeper and add a topper for the other, which is cheaper than buying twice.
What the types actually feel like
Innerspring beds are the traditional coil construction: bouncier, cooler, and usually the least expensive. Memory foam contours closely and isolates motion well, so a restless partner is less noticeable, but it can sleep warm. Hybrids put foam or latex layers over a coil base and try to split the difference, which is why they have become the most popular category. Pillow-top refers to an extra padded layer sewn on top, not to a construction, and it can appear on any of them.
Do not skip the ten minutes
Sit down for thirty seconds and every mattress feels fine. That is not a test, it is a greeting. Lie down in the position you actually sleep in, with a pillow, and stay there for a full ten minutes. Long enough for your shoulders to settle and for your lower back to tell you the truth.
What to pay attention to while you are down there:
- Is your spine roughly straight from neck to hips, or is something sagging?
- Can you roll over without shoving?
- If you sleep on your side, does your shoulder feel pressed or supported?
- If someone shares the bed, have them lie down too and move around
Take your shoes off. Bring your own pillow if you have a strong opinion about pillows. Nobody at LQ is going to hurry you off a mattress, and our sleep gallery runs along the back of the building precisely so you can lie down on as many as you need to.
Adjustable bases
An adjustable base raises the head and foot, which helps with snoring, acid reflux, circulation, and reading in bed. Most modern foam and hybrid mattresses work on one; traditional innersprings with a rigid border often do not. If an adjustable base is on your list, test the mattress on the base rather than on a flat foundation, because the feel changes.
When to replace the one you have
Most mattresses have roughly seven to ten useful years in them. The clearer signals are physical: a visible dip or body impression that stays after you get up, waking with stiffness that fades during the day, or sleeping noticeably better in a hotel bed. If you are reading this because your back hurts every morning, that is your answer.
Come lie down
We carry most of the name brands you already know at warehouse prices, and the tag price is the price. Walk in Wednesday through Saturday 10 to 6 or Sunday 12 to 6, no appointment, and give yourself an hour. Bring your room measurements, take your shoes off, and use the ten minutes. If a mattress is the big purchase this year, financing runs four ways.