Online RulerConvert Inches to Centimeters
Multiply inches by 2.54 to get centimeters. One inch equals exactly 25.4 millimeters, which is 2.54 centimeters. If the inch measurement includes a fraction, divide the top number by the bottom number, add the result to any whole inches, and then multiply.
- The conversion factor from inches to centimeters is exactly 2.54.
- Whole inches, decimal inches, and fractional inches use the same factor.
- Keep the digits through the calculation and round the centimeter reading only when you are ready to record it.
- Write down the inch reading as it appears on the ruler, including any fraction after the whole number.
- For a fraction, divide its numerator by its denominator. Add that value to the whole inches, if any.
- Multiply the full inch value by 2.54. On a calculator, you can put the fraction and whole inches in parentheses before multiplying.
- Label the result cm. Keep the original reading nearby if you need to check it against the ruler again.
Read a fractional inch
Find the whole inch mark just before the endpoint. Read the remaining distance from that mark using the small ticks. If the endpoint is between ticks, record how closely you can read it. Enter the fraction as division and include the whole inches before you multiply. Check the calculator entry if you used a space between the whole number and fraction on paper, since the space alone may not express addition.
Round after multiplying
A calculator can display more decimal places than you can read on a ruler. Keep the full result while you compare values or carry out more arithmetic. When you record the final length, round to a place that makes sense for the original reading and the job. For a close fit, keep the original measurement with the converted value so you can check which marks you actually read. Apply the same units when comparing the part and the opening.
Read centimeters on screen
If you are taking a new measurement, choose centimeters on the AR Ruler website or on its desktop or extension ruler. Place one edge of the object at the fixed zero and slide the marker to the opposite edge to read its length. If you already have a measurement written in inches, use the calculation directly. Verify the screen calibration before taking a new reading after a browser zoom or display change.
How do I convert centimeters back to inches?
Divide the centimeter value by 2.54. Keep any needed decimal places until you finish the calculation.
Do I multiply by 25.4 or 2.54?
Use 25.4 for millimeters and 2.54 for centimeters. Label the result with the unit you chose so you can check it later.
Can I convert a part's width and height?
Yes. Multiply each inch measurement by 2.54 separately. Keep the width and height labels beside their results so each value stays with the correct edge.