平方公里即平方千米（Square kilometer）是公制面积单位。其定义是：边长为1千米的正方形的面积，也是测量土地的单位，简写为km²。
平方米平方米在港台地区称为平方米，是面积的公制单位。英文：square meter，用m²符号表示，定义为边长为1米的正方形的面积。在生活中平方米通常简称为“平米”或“平方”。
平方千米转平方米换算表平方千米 (km²)平方米 (m²)0.1 km²100000 m²0.5 km²500000 m²1 km²1000000 m²1.5 km²1500000 m²2 km²2000000 m²3 km²3000000 m²4 km²4000000 m²5 km²5000000 m²6 km²6000000 m²7 km²7000000 m²8 km²8000000 m²9 km²9000000 m²10 km²10000000 m²11 km²11000000 m²12 km²12000000 m²13 km²13000000 m²14 km²14000000 m²15 km²15000000 m²16 km²16000000 m²17 km²17000000 m²18 km²18000000 m²19 km²19000000 m²20 km²20000000 m²25 km²25000000 m²30 km²30000000 m²35 km²35000000 m²40 km²40000000 m²45 km²45000000 m²50 km²50000000 m²平方千米 (km²)平方米 (m²)55 km²55000000 m²60 km²60000000 m²65 km²65000000 m²70 km²70000000 m²75 km²75000000 m²80 km²80000000 m²85 km²85000000 m²90 km²90000000 m²95 km²95000000 m²100 km²100000000 m²150 km²150000000 m²200 km²200000000 m²250 km²250000000 m²300 km²300000000 m²350 km²350000000 m²400 km²400000000 m²450 km²450000000 m²500 km²500000000 m²550 km²550000000 m²600 km²600000000 m²650 km²650000000 m²700 km²700000000 m²750 km²750000000 m²800 km²800000000 m²850 km²850000000 m²900 km²900000000 m²950 km²950000000 m²1000 km²1000000000 m²5000 km²5000000000 m²