Inches to cm Converter (Includes Feet and Inches)

Why 2.54 is exact, and how to handle feet and inches

Since 1959 the international inch has been defined as exactly 2.54 centimeters. That makes inch to centimeter conversion a plain multiplication with no rounding in the factor. Multiply inches by 2.54 to get centimeters, and divide centimeters by 2.54 to get inches. The one-foot length of 12 inches is exactly 30.48 cm, and a yard is exactly 91.44 cm.

Worked example: a height of 5 feet 8 inches. Convert the feet first, 5 times 12 is 60 inches, then add 8 to get 68 inches. Multiply 68 by 2.54 and you get 172.72 cm. The converter does this in one step when you pick the feet and inches mode. Going the other way, 180 cm divided by 2.54 is 70.87 inches, or 5 feet 10.9 inches.

Shoppers meet this conversion on furniture, clothing and luggage. A 22 inch carry-on is 55.9 cm, and a 62 inch luggage total, covered by the linear inches calculator, is 157.5 cm. For fractions, 1/8 inch is 3.175 mm. When you need a rough check, think of an inch as two and a half centimeters, and add a little. Tailors, woodworkers and shoppers use the same factor for sleeves, shelves and screens, so a single tool covers all of them. For long distances see the miles to km converter.

The table below lists typical heights and furniture sizes in both units so you can check a result at a glance. Reference table for common lengths and heights, plain HTML so it works without JavaScript.

Where these numbers come from

The formulas and default values in this calculator are based on:

• NIST SP 811 Appendix B8, conversion factors (nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8) (inch and foot are exact)
• NIST unit conversion guidance (nist.gov/pml/owm/metric-si/unit-conversion). Note: feet and inches output is rounded to 0.1 inch

This is a planning estimate, not medical, legal or immigration advice. Fees, allowances, limits and entry rules change, so confirm the figures with your airline, cruise line, customs agency or the official government source before you book or travel, and follow their rules if they differ from this page.