A meter (m) is a metric unit of length equal to 100 centimeters. It is the base unit of length in the metric system, a little over three feet (about 3.28 feet). A doorway is about 2 meters tall, and 1,000 meters make a kilometer. To change meters to centimeters, multiply by 100.
A meter is 100 centimeters, just a bit longer than a yard. Two meter sticks stacked end to end reach about the top of a doorway.
Formal definition and notation
The meter is the base unit of length in the International System of Units (SI). Other metric lengths are built from it with prefixes: a centimeter is one hundredth of a meter, a millimeter one thousandth, and a kilometer 1,000 meters. NIST states the official definition: the meter is defined by fixing the speed of light in a vacuum at exactly 299,792,458 meters per second.
Symbol
Read it as
Meaning
m
meter or meters
the unit symbol, lowercase, with no period (3 m, not 3 m. or 3 ms)
A meter is a little longer than a yard: 1 m is about 1.09 yards, or about 3.28 feet.
Benchmarks: a doorway is about 2 meters tall, and a typical classroom ceiling is about 3 meters high.
Metric conversions are powers of 10, so you only move the decimal point: 3.2 m = 320 cm = 3,200 mm.
Area and volume units change faster: 1 m2 = 10,000 cm2 and 1 m3 = 1,000,000 cm3.
The spelling metre is used in British English; the symbol m is the same everywhere.
Meter conversions
Meter conversions
1 m = 100 cm = 1,000 mm
m to cm
multiply by 100
cm to m
divide by 100
m to mm
multiply by 1,000
m to km
divide by 1,000
Moving to a smaller unit makes the number bigger: 1.75 m = 175 cm. Moving to a bigger unit makes it smaller: 450 m = 0.45 km.
Try it: convert meters
Interactive
Type a length and choose the units. The staircase shows that each step down multiplies by 10. Try 1.75 meters to centimeters, then to millimeters and kilometers.
This interactive needs JavaScript. The worked examples below show the same ideas step by step.
Meter examples, step by step
Example 1: Meters to centimeters
Warm-up
A board is 3.6 m long. How many centimeters is that?
Each meter is 100 cm, so multiply by 100.
3.6 × 100 = 360: the decimal point moves 2 places right.
Sense check: centimeters are smaller, so the number should be larger.
Answer: The board is 360 cm long.
Example 2: Millimeters to meters
Core
A desk is 2,450 mm wide. Write the width in meters.
There are 1,000 mm in a meter, so divide by 1,000.
2,450 ÷ 1,000 = 2.45: the decimal point moves 3 places left.
Check: 2.45 m is between 2 m (2,000 mm) and 3 m (3,000 mm).
Answer: The desk is 2.45 m wide.
Example 3: Fence panels
Test-style
A garden is 4.5 m long and 3 m wide. Fencing comes in panels 50 cm long. How many panels are needed to go all the way around?
A kilometer is 1,000 meters, used for long distances. A 5 km race is 5,000 m.
Metervs.Yard
A yard is a U.S. customary unit of 3 feet, about 0.91 m. A meter is about 1.09 yards, so a meter is slightly longer.
Quick check: 3 questions
Question 1 of 3
How many centimeters are in 4.2 m?
Show answer and explanation
Answer: B. Multiply by 100: 4.2 × 100 = 420 cm. 42 multiplies by 10, 4,200 by 1,000 (that is millimeters), and 0.042 divides instead of multiplying.
Question 2 of 3
Which is the best estimate for the height of a classroom door?
Show answer and explanation
Answer: C. A doorway is a little taller than an adult, about 2 m. 2 cm is the size of a coin, 20 m is about the height of a 6-story building, and 2 km is a long walk.
Question 3 of 3
A ribbon is 1.5 m long. You cut off 65 cm. How much is left?
Show answer and explanation
Answer: A. Convert first: 1.5 m = 150 cm, and 150 − 65 = 85 cm. 63.5 cm subtracts 1.5 from 65 without converting, 935 cm treats 1.5 m as 1,000 cm, and 0.85 cm confuses meters with centimeters.
Meter: frequently asked questions
How long is a meter in feet?
A meter is about 3.28 feet, or a little over 3 feet 3 inches. It is also about 1.09 yards, so a meter stick is slightly longer than a yardstick. Going the other way, a foot is about 0.3 m and a yard is about 0.91 m. These conversions are rounded, so answers using them are approximations.
How many centimeters and millimeters are in a meter?
There are 100 centimeters and 1,000 millimeters in one meter. To change meters to centimeters, multiply by 100 (move the decimal point 2 places right): 0.8 m = 80 cm. To change meters to millimeters, multiply by 1,000: 0.8 m = 800 mm. Divide to go back.
How is the meter defined?
According to NIST, the meter is defined by fixing the speed of light in a vacuum at exactly 299,792,458 meters per second. So a meter is the distance light travels in a vacuum in 1 / 299,792,458 of a second. This definition lets any well-equipped lab reproduce the meter exactly, without a physical master bar.
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