google search antec power supply calculater
It's still useless because it doesn't show the combined +12 Volt continuous current rating required on the power supply.
Total Power Supply Wattage is NOT a crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important.
The Recommended PSU Wattage shown by that calculator just gives you a general idea on what to look for.