PC Power Supply Calculator – Recommended PSU Wattage

Calculate recommended power supply wattage for any PC build.

CPU TDP (watts)

GPU TDP (watts)

RAM modules × 5W each

Storage devices × 5W each

Other components (fans, RGB, etc.)

About This Calculator

Calculate recommended power supply wattage for any PC build. Use the calculator above for instant results.

Worked Examples

Example 1: 125W CPU + 300W GPU + 4 RAM + 3 SSDs

Total: 125+300+20+15+30 = 490W
Recommended: 650W PSU (25% headroom)

Answer: 650W PSU recommended

Example 2: 65W CPU + 150W budget GPU + 16GB RAM

Total: 65+150+10+15+30 = 270W | Recommended: 350W

Answer: 350W PSU

Example 3: High-end: 250W CPU + 450W GPU

Total: 250+450+20+15+30 = 765W | Recommended: 1000W

Answer: 1000W PSU

Who Uses This Calculator?

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PC Builders

Choose correct PSU for build.

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Enthusiasts

Avoid underpowering components.

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System Integrators

Spec PSU for custom builds.

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Gamers

Right-size PSU for gaming rigs.

Common Mistakes to Avoid

❌ TDP is maximum, not average

Average gaming power is 60-80% of TDP. However, PSU should handle peaks without shutting down.

❌ Cheap PSU risks system stability

Always buy 80 PLUS Bronze or better from reputable brands (Seasonic, Corsair, EVGA, be quiet!). Cheap PSUs can fail catastrophically.

Frequently Asked Questions

Why 25% headroom?

PSUs are most efficient at 50-80% load. Headroom prevents overload on power spikes. Adds room for upgrades.

80 PLUS certification?

80 PLUS: 80% efficient. Bronze: 82-85%. Gold: 87-90%. Platinum: 90-92%. Titanium: 94%. Higher efficiency = less heat and lower electricity bills.

Modular vs non-modular?

Full modular: cleanest builds, pay premium. Semi-modular: good balance. Non-modular: cheapest, messier cables. Get modular if budget allows.