You will usually use a ruler or tape measure to make measurements in centimeters. There are also methods for estimating length in centimeters and for converting measurements made with other units to the equivalent value in centimeters.
Steps
Method 1 of 4: Method 1: Take a Measurement in Centimeters
Step 1. Look at the numbers on the ruler
Each number on the ruler corresponds to one centimeter.
Rulers only measure in centimeters and millimeters, so they are usually used for centimeter measurements. You can also use a tape measure instead of the ruler
Step 2. Note the smaller lines between the numbers
Each small line between integers on a ruler corresponds to one millimeter, which is one tenth of a centimeter.
1 mm equals 0.1 cm
Step 3. Put the edge of the ruler on the edge of the object to be measured
To measure the length of an object in centimeters with a ruler, you must first make the “0” of the ruler coincide with the beginning of the side of the object to be measured.
- Keep the ruler flat and parallel to the side of the object being measured.
- There may not even be written "0" on the ruler, but the side of the "0" is the one closest to the "1 cm" measurement.
Step 4. Read the number corresponding to the opposite edge of the object to be measured
This way you can find the length of the object in centimeters.
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If the edge of the object coincides with an integer, the object size is an integer value expressed in centimeters.
Example: If the length of an object is from 0 to number 4, that object is exactly 4 cm long
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If the edge of the object coincides with one of the smaller lines, the length of the object will be equal to the sum of the last whole number of centimeters plus the value of the small line, measured in tenths of a centimeter (millimeters).
Example: If the length of an object is from 0 to the third dash after the number 4, the length will be 4.3 cm
Method 2 of 4: Method 2: Estimate Centimeters
Step 1. Note that some items measure approximately 1cm
If you don't have a ruler or tape measure but need to estimate the length of an object in centimeters, you can use an object that you know is about 1 centimeter.
- One of the easiest items to find is a pencil, pen or highlighter. The diameter of a standard pencil is approximately 1 cm.
- Other ideas are the width of a paper clip, the thickness of five CDs or DVDs stuck together, the thickness of a standard notepad, the radius of an American penny.
Step 2. Put the object to be measured on a sheet of paper
Place the object on a sheet of white or light-colored paper. Make sure the whole object fits on the paper.
- Mark the edge of the object with a pencil or pen (not the one you use to measure).
- The card must be clear, so that you can clearly see the marks made.
Step 3. Place the object you are measuring against the edge you want to start from
Align one of the edges of the object you use to measure with the edge of the object you are measuring.
For example, if you use a pencil to estimate centimeters, place it perpendicular to the edge of the object you are measuring, so that its eraser or tip is against the side to be measured. One side of the pencil should be against the side of the object to be measured, while the other should extend inward along the side that will be measured
Step 4. Make a mark on the opposite side of the object you use to measure
On the opposite side of the object you use to measure, make a pencil or pen dot, placing it as close as possible to the object used to measure.
Step 5. Move the object used to measure
Take it and reposition it so that its side matches the mark you just made. Make another mark on the opposite side.
- Make sure the object you use to measure remains perpendicular to the other every time you move it. The object to be measured must remain in the same position all the time.
- Repeat the process until you reach the end of the object to be measured.
- Make sure that the end point of the object you are measuring is also marked.
Step 6. Count the spaces
When you're done, remove both objects from the paper. Count the number of spaces between the marks you made. This number corresponds to the estimate of the measurement in centimeters of the object.
You have to count the spaces, not the signs
Method 3 of 4: Method 3: Convert other Length Units to Centimeters
Step 1. Convert millimeters to centimeters
There are 10 millimeters in 1 centimeter.
- To convert a measurement in millimeters to one in centimeters, you need to divide the measurement by 10.
- Example: 583 mm: 10 = 58.33 cm
Step 2. Learn to convert meters to centimeters
There are 100 centimeters in 1 meter.
- To convert a measurement in meters to an equivalent measurement in centimeters, you need to multiply by 100.
- Example: 5.1m x 100 = 510cm
Step 3. Calculate centimeters from kilometers
There are 100,000 centimeters in 1 kilometer.
- If you want to convert a measurement made in kilometers into an equivalent measurement in centimeters, you have to multiply by 100,000.
- Example: 2, 78 km x 100,000 = 278,000 cm
Method 4 of 4: Method 4: Convert Imperial Measurements to Centimeters
Step 1. Convert inches to centimeters
One inch equals 2.54 centimeters. However, this value is not constant, so you will need a special conversion factor to convert inches to centimeters.
- If you need to convert an inch measurement to an equivalent centimeter value, you need to divide the inch value by 0.39370.
- Example: 9.41 inches: 0.39370 = 23.9 cm
Step 2. Calculate the centimeters from the feet
1 foot corresponds to 30, 48 centimeters. As with inches, the rate isn't constant, so you'll need to use another conversion factor.
- To convert a measurement in feet into an equivalent value in centimeters, divide the number by 0.032808.
- Example: 7.2 feet: 0.032808 = 219.46cm
Step 3. Learn to convert yards to centimeters
1 yard equals 91.44 centimeters. As with other imperial to meter conversions, you will need to use another conversion factor to convert yards to centimeters.
- If you want to convert a yardage measurement to centimeters, divide the value by 0.010936.
- Example: 3.51 yards: 0.010936 = 320.96 cm
