All SpecsCalc Tools
Free, data-driven calculators for building and tuning a PC — each one gives a real, verifiable answer, not a generic number.
PC Part Compatibility Checker
Check socket, RAM, GPU clearance, cooler, PSU and power connectors.
Auto PC Builder
Budget-to-parts list, balanced and well-balanced, $500–$2000+.
Bottleneck Estimator
Honest CPU/GPU balance by resolution, game type and upscaling.
PSU Wattage Calculator
Recommended power-supply size with a transient-safe buffer.
LLM VRAM Calculator
Will a local AI model fit your GPU? Weights + KV cache + overhead.
SFF GPU Clearance Checker
Does that GPU fit your small case? Length, thickness, height, bend.
RAM Latency Calculator
True latency in ns — compare DDR4 and DDR5 kits fairly.
FPS & Frame-time Calculator
Convert FPS to ms and see which refresh rates you saturate.
Valorant ↔ CS2 Sensitivity
Carry the exact same aim between Valorant and CS2.
What PSU for Each GPU
The exact power supply your specific graphics card needs.
Does Your GPU Fit SFF?
Small-case compatibility for any popular graphics card.
Best PC for Your Game
Recommended build for 20+ popular games, by workload.
Build by Resolution
The right build for 1080p, 1440p, 4K or a tight budget.
Is Your CPU Good for Gaming?
Gaming verdict and the ideal GPU pairing for popular CPUs.
GPU vs GPU Compare
Head-to-head: performance, VRAM, power and which to buy.
PC Parts Buying Guides
How to pick a PSU, RAM, SSD and cooler — by build tier.
Is Your GPU Good for 4K?
Per-card verdict for 1080p, 1440p and 4K gaming.
CPU vs CPU Compare
Head-to-head gaming verdict for popular processors.
Build Cost Calculator
The true total cost: tower + Windows, monitor and peripherals.
CPU + GPU Bottleneck
Popular pairings rated balanced or bottlenecked.
New to building? Start with the No-Bottleneck PC Building Guide.
What these tools do differently
Every calculator here runs entirely in your browser, takes no account and stores nothing on a server. More importantly, each one is built to refuse the answer it cannot support honestly.
- The bottleneck estimator returns a band and the reasoning behind it, never a percentage, because tier indices cannot produce a percentage honestly.
- The clearance checker reports unknown when a manufacturer has not published a required limit, instead of estimating a pass from slot count.
- The PSU calculator shows the peak draw it calculated alongside the recommendation, so you can see how much of the result is headroom.
- The VRAM calculator separates weights, KV cache and overhead, because the term that breaks a fit is usually not the one people check.
Where a figure is a manufacturer specification it is labelled as one; where it is our own model, the model is published. The in-depth guides work through the arithmetic behind each tool, and the methodology page sets out the limits of all of them.