Computer Power Calculator
Sums the peak DC draw of every PC component, adds headroom, rounds up to a standard power-supply size floored by the GPU maker's minimum, and reports PSU load, AC wall draw at a chosen 80 PLUS efficiency and the ATX 3.x transient budget.
Your figures
Updates as you typeHow this is worked out
7 steps
- Component peak sum = CPU 181 + GPU 304 + motherboard 40 + RAM 2 x 6 = 12 + SSD 1 x 5.5 = 5.5 + HDD 0 x 5.1 = 0 + fans 3 x 1.68 = 5.04 + pump 2.7 + USB 0 = 550.24 W DC
- Target = 550.24 x (1 + 20/100) = 660.288 W
- Smallest standard size >= 660.288 W is 750 W; recommended = max(750, vendor minimum 750) = 750 W
- PSU load at the component sum = 550.24 / 750 = 73.37 %
- AC wall draw = 550.24 / 0.9 (80 PLUS Gold, 115 V, 50 % column) = 611.38 W; heat = 61.14 W
- ATX 3.x excursion budget (Table 3-3, >450 W with 12V-2x6) = 750 W x 2 / 1.8 / 1.6 / 1.2 for 100 us / 1 ms / 10 ms / 100 ms
- Cross-check (Corsair rule): 304 + 181 + 150 + 150 = 785 W -> 850 W
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
9 sources
What this calculator does
Sums the peak DC draw of every PC component, adds headroom, rounds up to a standard power-supply size floored by the GPU maker's minimum, and reports PSU load, AC wall draw at a chosen 80 PLUS efficiency and the ATX 3.x transient budget.
How to use Computer Power Calculator
Enter Processor, Custom CPU peak power, Graphics card, Custom GPU board power, Custom GPU maker minimum PSU, Motherboard, VRM losses and chipset, Memory modules (DIMMs), Power per DIMM, Solid-state drives, Power per SSD, 3.5-inch hard disks, Power per hard disk, Case and CPU-cooler fans, Power per fan, AIO or water-cooling pump, Bus-powered USB peripherals, Headroom above the component sum, 80 PLUS level (for AC wall draw only), Mains supply and 80 PLUS load column for the efficiency figure. The calculator checks the values, applies the stated method, and updates the result without saving your figures.
What the result means
The result includes Recommended PSU rating, Component peak sum (DC), Target with headroom, Next standard size above the target, GPU maker minimum PSU, PSU load at the component sum, 80 PLUS efficiency used, AC wall draw at that efficiency, Heat lost in the PSU, ATX 3.x excursion budget, 100 microseconds, ATX 3.x excursion budget, 1 millisecond, ATX 3.x excursion budget, 10 milliseconds, ATX 3.x excursion budget, 100 milliseconds, Cross-check: Corsair GPU + CPU + 150 + 150 rule and How the size was reached. Review the visible working and any warnings before using the answer for a decision.
Method and checks
The method cites NVIDIA GeForce RTX 50-series specification pages (Total Graphics Power, Required System Power); AMD Radeon RX 9070 XT / RX 9070 product pages (Typical Board Power, Minimum PSU Recommendation); Intel processor specifications (Processor Base Power, Maximum Turbo Power) and support article 000089297 (TDP = Processor Base Power), among others. Its 5 built-in worked examples are checked on every full test run. The initial answer and working are rendered on the server, so they remain readable without JavaScript.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
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