Computer Wattage Calculator: Estimate Your PC’s Power Consumption
Use the calculator to enter each PC part, add RAM, storage and cooling, then read the total watts and PSU size. A gaming build with an RTX 4090 alone can draw 350 W from the GPU (Nvidia GeForce RTX 4090 Specs, 2023). The tool adds every component, applies a 20 % overclock factor and a 30 % safety buffer, so you avoid freezes and overspending.
Computer Wattage Calculator
Estimated Wattage:
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Tap the Share button at the bottom of the browser
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How to use the tool
Pick a CPU: Choose the wattage closest to your processor. Example inputs: AMD Ryzen 5 7600 (88 W) or Intel Core i9-13900K (125 W).
Select a GPU: Match the nearest class. Sample picks: Nvidia RTX 4070 (200 W) or AMD RX 7900 XTX (355 W).
Enter RAM sticks: Count modules, not capacity—e.g., 4 or 8.
Add storage drives: Enter the number of HDDs and SSDs separately.
Fans & cooling: Type fan count, tick “Liquid Cooling” if a pump is present.
Overclocking: Check the box when you raise CPU/GPU frequencies.
Press “Calculate Wattage”: Read the estimated draw and the recommended PSU size.
Why does the calculator add 50 W for the motherboard?
Your board powers VRMs, chipset and I/O; modern ATX boards consume 40-60 W under load (Tom’s Hardware, 2022).
What is the purpose of the 30 % safety buffer?
The buffer covers capacitor aging and power spikes; ATX Spec 3.0 allows 200 % GPU spikes for 100 µs (PCI-SIG, 2023).
How does overclocking factor affect the result?
The 1.2 multiplier reflects a ~20 % power rise, similar to Intel’s PL2 boost behaviour (Intel XTU Guide, 2023).
When should you choose a higher-wattage PSU?
Select the next tier if you plan GPU upgrades or add drives; PSUs run most efficiently at 40-60 % load (Corsair Blog, 2023).
Does liquid cooling always add 10 W?
Yes, pumps draw 6-15 W; 10 W is the median for 240 mm AIO units (EKWB Specs, 2022).
Are the RAM and fan power numbers realistic?
DDR4 sticks draw 2-4 W each, and 120 mm fans sip around 2 W (Kingston Whitepaper, 2021; Noctua Datasheet, 2022).
What happens if the PSU is undersized?
Undersized units shut down or ripple voltage, risking data loss and component stress (Seasonic FAQ, 2023).
How do I factor PSU efficiency into cost?
Multiply load watts by rac{1}{efficiency}; a 600 W load on an 80 Plus Gold PSU draws 667 W from the wall (80 PLUS Program, 2023).
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