Queen size mattresses have become the golden standard in the mattress industry, and most manufacturers advertise with their Queen mattress prices. The reason why is the Queen size has become the most common model providing a good balance of sleeping area, floor space, and value. For example, a King size might be more spacious but it is also more expensive and takes up more space in the bedroom, and although some couples may be able to share a Full they will certainly be more comfortable in a Queen and the price difference is usually quite small. In fact, the Queen size tends to be the best value when you consider price per square inch, mainly as a result of demand and advertising.
So if you are like most mattress buyers, you should probably begin your research with the Queen size. It will be easiest to compare prices, and is likely the best size for your needs. Couples can sleep comfortably in the spaciousness of a Queen, and single sleepers will probably find a Queen mattress excessively spacious, but the difference in cost is usually negligible and worth not having to upgrade in the future. So when shopping for your new mattress, you should consider the benefits of the Queen and shift from there if you have outlying needs.