Mattress Size Reference Guide

The International Sleep Products Association (ISPA) is a trade association comprised of mattress
manufacturers and suppliers. Like many other major brands, Paramount Sleep is a long-standing
partner of ISPA. ISPA’s goal is to support innovation and growth across the sleep products
industry.

ISPA has established standards for mattress sizes that include allowable variances. Below is a
detailed explanation of these standards.

twin-size

ISPA VARIATION STANDARDS

Paramount Sleep adheres to ISPA standards and sizing variances on all mattress designs. The chart below outlines mattress sizes as per industry standards with acceptable variance ranges.

*All dimensions are in inches.
*If a ”bunkie” foundation is used, it shall have the same width, length, and tolerances as the finished twin-size box spring.
*Finished sizes are measured from outside to outside of tape edge at the centerlines of the width and length.
*The distance is measured between extreme outside edges of finished construction.
*The following dimensional tolerances apply to both length and width: up to 60″, + 3/4″, -1/2″; over 60″, + 1″, -3/4″; the corner radius is 3″.

HOW TO MEASURE A MATTRESS

Remove all sheets, blankets, pillows, and mattress protectors from the mattress.
1
Use a tape measure or fabric ruler to measure across the top quilt of the mattress from side to side. Then measure the short side of the mattress from corner to corner.
2
Measure the top quilt from the head of the mattress to the foot. Then measure the long side of the mattress from corner to corner.
3
Measure from the bottom of the mattress to the crown of the mattress quilt (not from tape edge to tape edge).