how many watt psu do i need to buy

[Monkeymenn]

i currently have this in my pc:
Intel Core i5 6400 2.7GHz / max. 3.3GHz (Skylake) Quad Core Processor
Gigabyte GA-H110M-S2H DDR4 Moederbord
8GB DDR4 2133MHz Geheugen
120GB SSD S-ATAIII
1000GB S-ATAIII 7200rpm Harddisk
DVD±ReWriter Dual Layer
Gigabit Netwerk en 5.1 HD Geluid onboard
Intel® HD Graphics 530 onboard
420watt ATX Voeding

now i wanna get a graphics card the asus gtx 950 strix.
only i don't know how many watt i need in my computer.

 

[Endless8]

Hi,
430W is enough for your build, but your PSU is a bad quality and it may not have 430W in real, so there is a risk that your PC will not work correctly.
Cheers.