Number + 米
The measure word 米 (mǐ) is used to count meters as a unit of length. In Chinese, 米 functions as a classifier placed directly after a number to express distance or dimensions. Simply place a number before 米 to indicate a measurement in meters.
这条河大概有五十米宽。
zhè tiáo hé dàgài yǒu wǔshí mǐ kuān.
This river is about fifty meters wide.
他跑了一百米只用了十二秒。
tā pǎo le yībǎi mǐ zhǐ yòng le shí'èr miǎo.
He ran a hundred meters in just twelve seconds.
我家离地铁站不到三百米,很方便。
wǒ jiā lí dìtiě zhàn bú dào sānbǎi mǐ, hěn fāngbiàn.
My home is less than three hundred meters from the subway station — very convenient.