Convert centimeters to decimeters

The starting point for both units is the meter cut into equal parts. Cutting it into a hundred gives the centimeter, cutting it into ten gives the decimeter[1]. That is why one decimeter holds ten centimeters.

The centimeter is the base unit of length in the centimetre–gram–second system, now deprecated, and it remains a practical unit for everyday measurement: human height is commonly given in centimeters[2]. One inch equals exactly 2.54 centimeters, so a centimeter comes to 0.3937 inches[2]. One cubic centimeter is one milliliter, so the same volume carries two names. The milliliters to liters converter handles that side of the family.

The decimeter covers lengths an order of magnitude larger. It earns its place where the count of centimeters climbs into the tens and working in tens is easier: on the scale of a measuring instrument, or on an area written in square decimeters.

For a reader raised on inches there is one figure worth keeping: a decimeter is 3.937 inches, a shade under four. Ten centimeters and just under four inches describe the same length, and that single pairing makes every row of the conversion table easy to picture.

A centimeter is 0.1 decimeters. Ten centimeters make exactly one decimeter. One hundred centimeters give ten decimeters, which is one meter.

Every conversion in this direction comes down to dividing the number of centimeters by ten. Twenty-five centimeters is 2.5 decimeters. Fifty centimeters gives 5 decimeters. Eighty centimeters is 8 decimeters.

For figures ending in zero you get the answer by striking that zero out, so those values you can quote from memory. Sixty centimeters gives 6 decimeters. Ninety centimeters is 9 decimeters. For every other figure the decimal point moves one place to the left, so 23.6 cm becomes 2.36 dm and 5.21 cm becomes 0.521 dm.

Values below one centimeter drop past the hundredths of a decimeter. Seven hundredths of a centimeter, written 0.07 cm, is 0.007 dm. The result field shows three decimal places for exactly that reason.

The result appears in the field alongside as you type, and the Swap order button turns the conversion round to decimeters and centimeters.

The conversion rests on one fixed relationship: ten centimeters make one decimeter. To turn centimeters into decimeters you divide their number by ten.

The full formula: decimeters = centimeters ÷ 10. The other way round: centimeters = decimeters × 10.

Three examples of different size follow from that formula. Twelve and a half centimeters divided by ten give 1.25 decimeters. One hundred centimeters is 10 decimeters. Five hundred and thirty-six centimeters gives 53.6 decimeters.

On paper the division is a single move. The digits stay as they are and the decimal point shifts one place to the left. From 47 centimeters you get 4.7 decimeters, and from 6.5 centimeters you get 0.65 decimeters. With a single digit in front, a zero takes its place before the point.

Going the other way the operation is reversed: you multiply by ten and the point travels one place to the right. That is exactly what the decimeters to centimeters converter does. If you want the answer in meters, the centimeters to meters converter gives it, and for the step down to millimeters there is the centimeters to millimeters converter.