Estimates · inference only

LLM VRAM Calculator

Open-weights model dropped this week? Estimate what it takes to run it — weights + KV cache + overhead — and which GPUs clear the bar.

HardwareMemoryFits?

How the estimate works

Weights ≈ params × bits ÷ 8 (a 27B model at Q4 ≈ 13.5 GB). KV cache scales with context length (estimated per-token from model size; GQA models use less). We add ~15% runtime overhead (CUDA buffers, activations, framework). Real usage varies by architecture and runtime (llama.cpp vs vLLM) — treat results as a planning estimate, not a guarantee. Training and fine-tuning need far more.

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