To measure a bed's size without a ruler, start by determining the length using a standard sheet of paper or a known object like a credit card. Place the sheet end-to-end along the bed's longest side and count how many sheets fit to estimate length in inches or feet. For width, use a credit card (3.5 inches wide) to measure across the bed's shorter side, counting how many cards span the width. Multiply the count by 3.5 to estimate inches. Height can be gauged by stacking hands vertically; each hand span (about 9 inches) multiplied by the stack height gives the approximate height.

Standard bed dimensions are regulated by organizations like the International Sleep Products Association (ISPA), which specifies common sizes such as twin (38x75 inches), full (54x75 inches), queen (60x80 inches), and king (76x80 inches). Using body parts or household items introduces minor measurement errors (±1-2 inches), but these methods suffice for general comparisons or purchasing purposes. For example, a queen bed’s width is roughly equivalent to 17 credit cards (17 x 3.5 = 59.5 inches), aligning closely with the standard 60-inch width. According to ISPA data, 72% of U.S. households use standard mattress sizes, making estimation methods based on common references reliable for most practical needs. This approach balances convenience with accuracy, ensuring users can approximate dimensions without specialized tools while adhering to industry norms.