UltimatePCTools

PC Power Supply (PSU) Calculator

A PSU calculator determines the minimum power supply wattage your PC needs by summing the TDP (thermal design power) of every component — CPU, GPU, RAM, storage, and fans — then adding a 25% safety buffer for efficiency losses and transient power spikes. The average gaming PC draws 400–600W at peak load, but high-end builds with RTX 5000 series GPUs can exceed 1,000W.

Undersizing your power supply is one of the most common PC building mistakes. A PSU running above 80% of its rated wattage operates outside its designed efficiency curve, generating more heat, wearing out capacitors faster, and increasing the risk of sudden shutdowns during GPU-intensive workloads like gaming or rendering. NVIDIA's official minimum recommendations for RTX 5000 series cards start at 750W for the RTX 5070 and reach 1,000W for the RTX 5090 — before CPU and system overhead are factored in.

Oversizing, on the other hand, costs more upfront but delivers tangible benefits: a 1,000W PSU powering a 500W system runs at 50% load, squarely inside the 50–80% sweet spot where 80 PLUS Gold and Platinum units hit their peak efficiency. The extra headroom also future-proofs your build for GPU upgrades.

This calculator uses official Intel, AMD, and NVIDIA TDP specifications. Select your CPU and GPU, configure RAM sticks, storage drives, and fans, then click Calculate to get an instant wattage recommendation with a full per-component breakdown and the 80 PLUS efficiency tier your next PSU should target.

PSU Wattage Calculator

Based on official TDP specs

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Intel 14th Gen
Intel 13th Gen
Intel 12th Gen
AMD Ryzen 7000
AMD Ryzen 5000
AMD Ryzen 3000
NVIDIA
AMD

⚠️ Please select both a CPU and GPU to calculate.

What PSU Wattage Do I Need?

The right PSU wattage depends on your CPU and GPU TDP plus other components. As a rule, add up all component TDPs and multiply by 1.25. The table below covers the most common gaming build configurations in 2025/2026.

Build TypeExampleMin. PSURecommended
Budget gamingi3-12100F + RTX 3060550W650W
Mid-range gamingRyzen 5 7600 + RTX 4070650W750W
High-end gamingi7-14700K + RTX 4080750W850W
Enthusiast gamingi9-14900K + RTX 4090850W1000W
Flagship (RTX 5090)i9-14900K + RTX 50901000W1200W
Workstation/CreatorRyzen 9 7950X + RX 7900 XTX850W1000W

How We Calculate PSU Wattage

Estimated draw = CPU TDP + GPU TDP + RAM + Storage + Cooling + Fans + Mobo + Peripherals
Peak draw = Estimated × 1.10 (transient spike headroom)
Recommended PSU = Peak × 1.25 → rounded up to nearest 50W

All CPU TDP values are sourced from Intel and AMD official specifications pages. GPU TDP values use the Total Board Power (TBP) figure from NVIDIA and AMD spec sheets. Overclocked systems add 10% to CPU and 10% to GPU draw. The 25% headroom ensures your PSU operates in its 50–80% load sweet spot for maximum efficiency and longevity.

What PSU Do You Need for RTX 5090, 5080, and 5070?

The RTX 5000 series is the most power-hungry GPU generation ever released. All three flagship cards use the 12V-2x6 connector and require a PSU with native support — adapters increase the risk of connector overheating under sustained load. The figures below are NVIDIA's official minimums; the “safe” column includes 25% headroom for a mid-range CPU (65–125W TDP) and base system components.

GPUTDPNVIDIA Min.Safe Pick
RTX 5090575W1,000W1,200W
RTX 5080360W850W1,000W
RTX 5070 Ti300W800W900W
RTX 5070250W750W850W
RTX 5060 Ti180W700W750W

Frequently Asked Questions

How do I calculate what PSU wattage I need?
Add up the TDP (thermal design power) of all your components: CPU, GPU, RAM, storage drives, fans, and motherboard. Multiply the total by 1.25 to add a 25% safety headroom for efficiency losses, transient spikes, and future upgrades. Round up to the nearest standard PSU size (550W, 650W, 750W, 850W, 1000W).
What PSU do I need for an RTX 5090?
The RTX 5090 has a 575W TDP — the highest consumer GPU ever made. With a high-end CPU like the i9-14900K (253W) and base system components (~120W), total peak draw can exceed 1,000W. NVIDIA officially recommends a 1,000W PSU minimum, but with 25% headroom for transient spikes, a 1,200W unit is the safe choice. The RTX 5090 uses the 12V-2x6 connector; ensure your PSU has native support.
What PSU do I need for an RTX 5080 or RTX 5070?
The RTX 5080 draws approximately 360W TDP. NVIDIA recommends 850W minimum; with headroom, a 1,000W PSU is ideal for most i7/i9 pairings. The RTX 5070 draws around 250W TDP. NVIDIA recommends 750W, making an 850W unit appropriate for most mid-to-high-end builds. Both use the 12V-2x6 connector.
What PSU do I need for an RTX 4070?
The RTX 4070 has a 200W TDP. Paired with a mid-range CPU (65–105W), base system power (~120W), and peripherals, the estimated draw is 400–450W. NVIDIA recommends a 650W PSU minimum for RTX 4070 builds. Our calculator adds 25% headroom and recommends a 650W–750W unit depending on your CPU.
Is it bad to have too much PSU wattage?
No. A higher-wattage PSU than needed does not waste power — PSUs only draw what the system demands. In fact, a PSU running at 40–80% of its rated capacity operates in its most efficient range. The downside of over-sizing is cost, not performance. A 1000W PSU powering a 400W system wastes minimal power.
What does PSU efficiency rating mean?
The 80 PLUS rating (Bronze, Silver, Gold, Platinum, Titanium) indicates how efficiently the PSU converts AC power from the wall to DC power for your components. An 80 PLUS Gold PSU is 87–92% efficient at 50% load, meaning it wastes 8–13% as heat. Platinum improves this to 90–94%. For high-wattage systems, Platinum reduces electricity cost and heat meaningfully.
Should I buy a modular or non-modular PSU?
Fully modular PSUs let you attach only the cables you need, improving airflow and cable management. Semi-modular units have the essential cables fixed and optional ones removable. Non-modular PSUs include all cables permanently. For mid-tower and full-tower builds, at least semi-modular is recommended. The power output is identical regardless of modularity.
Is 650W enough for most gaming PCs?
Yes — 650W covers the majority of mid-range gaming builds. A Ryzen 5 7600 paired with an RTX 4070 draws roughly 380W at peak, leaving 270W of headroom in a 650W unit. Where 650W falls short: RTX 4080 builds (need 850W), RTX 4090 builds (need 1000W+), and any RTX 5000 series GPU.

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