If you enjoy the softness of a traditional, coil-spring mattress, but also need the back support of a good solid carpeted floor, then a memory foam mattress provides the perfect middle ground. A memory foam mattress contains most of the cushioning and body forming capabilities of a regular mattress, with all the back support of a floor - perhaps even better than a floor, since memory foam obeys the contours of your spine.
Its tendency to soften with warmth and harden with coolness regulates how much support your body gets and where. You'll feel the greatest difference at the more jutting parts of your body, such as ankles, knees, hips, ribs, shoulders, elbows, finding less aches and pains in the morning. You'll find that there won't be as much morning numbness - your limbs will wake up when you do, as your overall circulation will be improved.
Twin Size Mattress
You'll sleep better. You'll live better.
But before you go smashing your piggy bank to spend everything on the first memory foam mattress you see, realize that not all memory foam mattresses are the same: they vary in density, thickness, and overall quality. Densities range from 2.5 pounds per cubic foot to 5 pounds per cubic foot in most cases, and as high as 5.3 or more for some of the premium brands. Denser mattresses tend to be more expensive because more raw material goes into them, and because fabricating them requires a finer science.
Denser mattresses are firmer and respond better to those who are thinner with more protruding bone structures, while mattresses that are less dense are softer and tend to do a better job at cradling curvier forms. If you do not tend to move around much while falling asleep, a denser mattress is ideal. For those who toss and turn a bit, a less dense mattress is the better choice. Do keep in mind that your tossing and turning may not actually be your natural way of sleeping, but rather a result of inadequate bedding. A middle-density memory foam mattress - about 4 pounds can accommodate a range of sleepers. Low-density memory foam mattresses (2.5-3.5 pounds per cubic foot) can sometimes "bottom out" and usually aren't worth the lower price.
As memory foam mattresses have gained in popularity, more luxurious (meaning thicker) beds have become more common. Your basic memory foam mattress uses a 5" base layer with a couple inches of foam at the top for any size, be it twin, twin-long, full-size, queen, king, or California king. More luxurious mattresses have a 6" base with an extra inch or two of top padding, for a more responsive feel, and these mattresses are the most popular memory foam beds. The top-of-the-line models also have a 6" base, but include extra top layering, for maximum responsiveness.
If you're looking to save money, finding a good discount memory foam mattress can be a difficult proposition. For a quality product, Consumer Reports recommends you spend at least 0 for a twin bed, 0 for a full-size bed, 0 for a queen, 00 for a king, and about 00 for a California king.
Major manufacturers tightly regulate retail pricing on their products. However, if you go through a smaller dealer or retailer, either at a brick-and-mortar location or online, you might be able to get the salesperson to throw in a free memory foam pillow, free shipping, or some other additional value to seal the deal.
Otherwise, if you are looking to save money on a memory foam mattress, try a manufacturer that makes lower-density mattresses. The quality will be lower than a denser mattress, but it might well be an improvement over the rusty bedsprings to which you've subjected yourself in the past.