Power supply for computer how much?

ok i dont know the how much power i need for my new computer its got a i5 3.10ghz xfx Radeon 6950 1gb Asus P8H61-M-LE-USB3-V3 Intel Mainboard (B3 Stepping) - 2x DDR3, 4x Sata, 2x USB3.0 1 tb hard drive 20 inch led screen lg bluray reader and dvd/cd... show more ok i dont know the how much power i need for my new computer

its got a i5 3.10ghz
xfx Radeon 6950 1gb
Asus P8H61-M-LE-USB3-V3 Intel Mainboard (B3 Stepping) - 2x DDR3, 4x Sata, 2x USB3.0
1 tb hard drive
20 inch led screen
lg bluray reader and dvd/cd burner combined
kingston drr3 4gb
and windows 7

what power supply should i get for it ?
8 answers 8