How many extra watts do I need to overclock?

Shadyxi

Prominent
Apr 16, 2017
74
0
660
Im looking to OC both my GPU and CPU, but not heavy overclocking. According to https://pcpartpicker.com/list/6dHZKZ my estimate wattage is around 336W and recommended me a 550W PSU.

Because I want to overclock I think 550W will not be enough. What PSU will be suitable for overclocking and wont melt my PC? Thanks!