# 5.5 Centimeter to Millimeter

Convert 5.5 (five) Centimeters to Millimeters (cm to mm) with our conversion calculator.

**5.5 Centimeters to Millimeters equals 55.00 mm.**

To convert length from centimeters (cm) to millimeters (mm), we use the conversion factor that 1 cm is equal to 10 mm. This conversion factor is based on the definition of the metric system where the prefix "milli" means one thousandth, thus there are 1000 millimeters in a meter and 100 centimeters in a meter—making the direct relationship between centimeters and millimeters as 1:10. Therefore, to convert 5.5 cm to millimeters, the calculation involves multiplying 5.5 by 10.

Performing this calculation, (5.5 \, \text{cm} \times 10 = 55 \, \text{mm}). This means that 5.5 centimeters is equal to 55 millimeters. This conversion is straightforward because you simply need to move one place to the right in the number when converting from centimeters to millimeters, or in other words, multiply by 10 according to the fundamental principles of the decimal system that the metric system is based upon.

Items that are 5.5 cm in length are surprisingly common in everyday life. Here are seven examples:

**A standard USB flash drive:**- Roughly the length of the metal part that plugs into the USB port.

**A large paperclip:**- When stretched out, the larger varieties can reach up to 5.5 cm.

**The diameter of a tennis ball:**- Considered to be in the range of 6.54–6.86 cm, but cheaper or smaller versions might be closer to 5.5 cm in diameter.

**A set of house keys:**- The length of a medium to large key.

**A small lipstick tube:**- Commonly around this length, especially the more compact versions.

**A matchbox:**- The standard small size box is approximately this length.

**An adult’s thumb (from tip to the first knuckle):**- Varies greatly among individuals, but many adult thumbs can be around 5.5 cm in length from tip to the first knuckle.

These items serve as real-world referents for visualizing the measurement of 5.5 cm, demonstrating its practical application in daily contexts.