Wire coils form the inner core of most mattresses, insulated by padding on either side. A higher coil count generally indicates a more supportive mattress, though there are many other factors to consider as well. Most innerspring mattresses contain between 250 and 1,000 coils.
Look for a mattress with a coil count between 312 and 540. Mattresses with coil counts of more than 540 tend to be of lower quality, since thinner wire is used to construct the coils in order to make room for them in the mattress and to save money. These coils also tend to be smaller and weaker, so a high coil count does not necessarily indicate a quality mattress. As a base line, look for full mattresses with coil counts of more than 300, queen mattresses with coil counts of more than 375 and king mattresses with counts of more than 450.
The coil count listed on your mattress’s label is often the coil count for a full-size mattress of the same style; if you are buying a larger or smaller mattress, know that this coil count will be higher or lower, respectively. Companies make it easier for you to compare mattresses this way, because this creates a universal industry standard across all innerspring mattresses.
Coil quality is determined by the gauge, tempering and how tightly wound the coils are. Consider these elements when choosing your mattress, as they can often be more indicative of quality than coil count. A mattress with a low coil count may be of good quality, if the coils in its core are thick, double heat tempered and tightly wound.
Coil design also affects coil count, since coil design determines the number of coils that fit in a mattress, without changing coil quality. For example, continuous coils are all shaped of one wire and remain connected; because of this design, these mattresses often can fit many more coils than mattresses with pocketed or hourglass coils—a difference that must be considered when comparing coil counts between these types of mattresses.