Content

• Steps
• Method 1 of 2: Simplified Conversion Process
• Method 2 of 2: Detailed Conversion Process
• Tips

You can find many converters of inches to centimeters on the Internet, each of which will inform you that 1 inch = 2.54 cm. However, this information is not always enough, and many teachers require you to write down the calculations. Fortunately, converting inches to centimeters is a fairly straightforward task. If the length is in inches, then simply plug the length in inches into the formula in this article to calculate the length in centimeters.

Steps

Method 1 of 2: Simplified Conversion Process

1. 1 Write down the length in inches. Either use the value given to you, or measure the length in inches with a ruler or tape measure.
2. 2 Multiply the length value by 2.54. One inch equals approximately 2.54 centimeters, so converting inches to centimeters means multiplying the value in inches by 2.54.
3. 3 Record "cm" as the new unit of measurement. Remember to write down the correct unit after the new value; otherwise, your answer will either not be accepted at all, or the grade will be lowered.

Method 2 of 2: Detailed Conversion Process

1. 1 Make sure the length is in inches. This may not seem like a big deal, but often the length is given in both feet and inches, denoted as 6'2 ". In such cases, the '' sign stands for feet, and one foot equals 12 inches.
   • In the above example (6'2 "), first we have to convert feet to inches: 6 (feet) x 12 (inches) = 72 inches, and then add inches given in the original value: 72 + 2 = 74 inches.
2. 2 Substitute the value in inches instead of a space in the following conversion factor:

   ____ inch

   *

   2.54 cm       1 inch

   =

   ? cm

   This conversion factor will give you the exact answer in centimeters and will satisfy the requirement to “write down the calculations” (if you are a student or high school student).
   • This conversion factor will also allow you to write the correct units. Note that inches in the denominator and inches in the numerator are canceled, leaving only centimeters in the numerator.
   • Let's substitute 74 inches from our example into this conversion factor.
     • (74 inches x 2.54 cm) / (1 inches)
     • (187.96 inches × centimeters) / (1 inch)
     • We are abbreviating inches because they are in both the numerator and denominator, and the final answer is 187.96 centimeters.
3. 3 Use a calculator if you don't need to write down the calculations. In this case, multiply inches by 2.54 on the calculator to convert inches to centimeters. This calculation repeats the above calculation (via a conversion factor) and you get the result in centimeters.
   • For example, if you want to convert 6 inches to centimeters, simply multiply 6 x 2.54 = 15.24 cm.
4. 4 For mental calculations, round off the conversion factor. If you don't have a calculator, you can convert inches to centimeters by rounding the conversion factor (to make multiplication easier in your head). Instead of using a conversion factor of 2.54, round up to 2.5.Please note that in this case you will not get an entirely accurate answer, so this method is only suitable for situations in which approximations are acceptable.
   • For example, convert 31 inches to centimeters using this quick conversion method:
     • 2,5 × 30 = 75; 2,5 × 1 = 2,5
     • 75 + 2.5 = 77.5 cm.
     • Note that using the exact conversion factor (2.54), you get an answer of 78.74 cm. That is, the difference between the two answers is 1.24 cm (or about 1.5%).

Tips

• 1 inch = 2.5399999 cm, so 1 inch = 2.54 cm is a very accurate approximation based on:
  • 1cm = 0.39370079 inches, i.e. 1cm = 4/10 inches (appr.)