medgemma-4b-it
google/medgemma-4b-itmedgemma-4b-it at Q4_K_M is exactly 2,489,893,664 bytes (2.32 GiB / 2.49 GB) — an effective 4.632 bits per weight, not the nominal 4. Its KV cache at 32K is 0.79 GiB, not the 4.25 GiB a flat formula predicts.
Shipped quantizations
| Quant | Size● | Exact bytes● | Effective bpw● | Tensors● | Publisher |
|---|---|---|---|---|---|
| UD-IQ1_S | 1.10 GiB | 1,183,392,320 | 2.202 | — | unsloth |
| UD-IQ1_M | 1.16 GiB | 1,242,579,520 | 2.312 | — | unsloth |
| UD-IQ2_XXS | 1.25 GiB | 1,344,119,360 | 2.501 | — | unsloth |
| UD-IQ2_M | 1.46 GiB | 1,567,883,840 | 2.917 | — | unsloth |
| IQ3_XXS | 1.57 GiB | 1,689,453,024 | 3.143 | — | bartowski |
| UD-IQ3_XXS | 1.59 GiB | 1,710,752,320 | 3.183 | — | unsloth |
| Q2_K | 1.61 GiB | 1,729,165,024 | 3.217 | — | bartowski |
| Q2_K_L | 1.61 GiB | 1,729,165,120 | 3.217 | — | unsloth |
| Q2_K | 1.61 GiB | 1,729,165,120 | 3.217 | — | unsloth |
| IQ3_XS | 1.74 GiB | 1,863,390,944 | 3.467 | — | bartowski |
| Q2_K_L | 1.76 GiB | 1,891,733,984 | 3.519 | — | bartowski |
| Q3_K_S | 1.80 GiB | 1,937,364,704 | 3.604 | — | bartowski |
| Q3_K_S | 1.80 GiB | 1,937,364,800 | 3.604 | — | unsloth |
| IQ3_M | 1.85 GiB | 1,986,803,424 | 3.696 | — | bartowski |
| Q3_K_M | 1.95 GiB | 2,098,460,384 | 3.904 | — | bartowski |
| Q3_K_M | 1.95 GiB | 2,098,460,480 | 3.904 | — | unsloth |
| Q3_K_L | 2.08 GiB | 2,236,085,024 | 4.160 | — | lmstudio-community |
| Q3_K_L | 2.08 GiB | 2,236,085,984 | 4.160 | — | bartowski |
| IQ4_XS | 2.11 GiB | 2,263,242,464 | 4.211 | — | bartowski |
| IQ4_XS | 2.11 GiB | 2,263,242,560 | 4.211 | — | unsloth |
| IQ4_NL | 2.20 GiB | 2,363,512,544 | 4.397 | — | bartowski |
| IQ4_NL | 2.20 GiB | 2,363,512,640 | 4.397 | — | unsloth |
| Q4_0 | 2.21 GiB | 2,370,066,144 | 4.409 | — | bartowski |
| Q4_0 | 2.21 GiB | 2,370,066,240 | 4.409 | — | unsloth |
| Q4_K_S | 2.21 GiB | 2,377,930,464 | 4.424 | — | bartowski |
| Q4_K_S | 2.21 GiB | 2,377,930,560 | 4.424 | — | unsloth |
| Q4_K_M | 2.32 GiB | 2,489,893,664 | 4.632 | — | lmstudio-community |
| Q4_K_M | 2.32 GiB | 2,489,894,624 | 4.632 | — | bartowski |
| Q4_K_M | 2.32 GiB | 2,489,894,720 | 4.632 | — | unsloth |
| Q4_1 | 2.39 GiB | 2,564,052,704 | 4.770 | — | bartowski |
| Q4_1 | 2.39 GiB | 2,564,052,800 | 4.770 | — | unsloth |
| Q4_K_L | 2.47 GiB | 2,652,463,584 | 4.935 | — | bartowski |
| Q5_K_S | 2.57 GiB | 2,764,592,864 | 5.143 | — | bartowski |
| Q5_K_S | 2.57 GiB | 2,764,592,960 | 5.143 | — | unsloth |
| Q5_K_M | 2.64 GiB | 2,829,698,784 | 5.264 | — | bartowski |
| Q5_K_M | 2.64 GiB | 2,829,698,880 | 5.264 | — | unsloth |
| Q5_K_L | 2.79 GiB | 2,992,267,744 | 5.567 | — | bartowski |
| Q6_K | 2.97 GiB | 3,190,739,744 | 5.936 | — | lmstudio-community |
| Q6_K | 2.97 GiB | 3,190,740,704 | 5.936 | — | bartowski |
| Q6_K | 2.97 GiB | 3,190,740,800 | 5.936 | — | unsloth |
KV cache by context
| Context | KV cache (f16)● | Flat formula | Overstated by | Full / windowed / recurrent |
|---|---|---|---|---|
| 4,096 | 0.25 GiB | 0.53 GiB | 2.14× | 5 / 29 / 0 |
| 8,192 | 0.33 GiB | 1.06 GiB | 3.26× | 5 / 29 / 0 |
| 16,384 | 0.48 GiB | 2.13 GiB | 4.40× | 5 / 29 / 0 |
| 32,768 | 0.79 GiB | 4.25 GiB | 5.35× | 5 / 29 / 0 |
| 65,536 | 1.42 GiB | 8.50 GiB | 5.99× | 5 / 29 / 0 |
| 131,072 | 2.67 GiB | 17.00 GiB | 6.37× | 5 / 29 / 0 |
29 of 34 layers cache only a 1,024-token window rather than the full context, on a period of 6. Figures assume the default configuration; --swa-full disables the saving entirely.
Compare with
Will it run on your card?
Why other calculators give a different number
A parameters × bits ÷ 8 estimate puts Q4_K_M at roughly 2.25 GiB. The real file is 2.32 GiB, because a quantization is a mixture and some tensors are always kept at higher precision. The larger discrepancy is the cache: a flat formula gives 4.25 GiB at 32K context where the real figure is 0.79 GiB, because most of this model's layers cache a fixed window rather than the whole context.
Architecture
Questions people ask
- How much VRAM does medgemma-4b-it need?
- Q4_K_M is exactly 2,489,893,664 bytes (2.32 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
- How large is medgemma-4b-it's KV cache?
- 0.79 GiB at 32K context with an f16 cache, computed per layer. Quantizing the cache to q8_0 roughly halves it, which is often the difference between a context length fitting and not.
- Which quantization of medgemma-4b-it should I use?
- Q4_K_M is the usual default. Pick the largest quantization that fits your card at the context you actually need — the table above gives exact sizes for every one published.