High volt dc measure

How can I measure 0-450 v DC using arduino.. :(

Use a voltage divider.

for 0-450 v DC measure you might need auto range, automatic voltage divider.

Let Arduino Yun Measure auto range DC voltage. (DCV: 0-4-40-400V±0.5%-1000V±0.8%)

http://forum.arduino.cc/index.php?topic=278719.0