gemma-3-1b-it
google/gemma-3-1b-itgemma-3-1b-it at Q4_K_M is exactly 806,058,240 bytes (0.75 GiB / 0.81 GB) — an effective 6.449 bits per weight, not the nominal 4. Its KV cache at 32K is 0.15 GiB, not the 0.81 GiB a flat formula predicts.
Shipped quantizations
| Quant | Size● | Exact bytes● | Effective bpw● | Tensors● | Publisher |
|---|---|---|---|---|---|
| UD-IQ1_S | 0.52 GiB | 557,014,304 | 4.457 | — | unsloth |
| UD-IQ1_M | 0.52 GiB | 559,813,664 | 4.479 | — | unsloth |
| UD-IQ2_XXS | 0.53 GiB | 564,479,264 | 4.516 | — | unsloth |
| UD-IQ2_M | 0.54 GiB | 578,024,480 | 4.625 | — | unsloth |
| UD-IQ3_XXS | 0.55 GiB | 591,648,032 | 4.734 | — | unsloth |
| Q3_K_S | 0.64 GiB | 688,856,096 | 5.511 | — | unsloth |
| Q2_K | 0.64 GiB | 689,814,560 | 5.519 | — | unsloth |
| Q2_K_L | 0.64 GiB | 689,814,560 | 5.519 | — | unsloth |
| IQ4_XS | 0.67 GiB | 714,435,104 | 5.716 | 340 | unsloth |
| IQ4_NL | 0.67 GiB | 721,863,200 | 5.776 | — | unsloth |
| Q4_0 | 0.67 GiB | 721,918,496 | 5.776 | — | unsloth |
| Q3_K_M | 0.67 GiB | 722,416,160 | 5.780 | 340 | unsloth |
| Q3_K_L | 0.70 GiB | 751,575,552 | 6.013 | — | lmstudio-community |
| Q4_1 | 0.71 GiB | 764,035,616 | 6.113 | — | unsloth |
| Q4_K_S | 0.73 GiB | 780,993,056 | 6.249 | — | unsloth |
| Q4_K_M | 0.75 GiB | 806,058,240 | 6.449 | 340 | ggml-org |
| Q4_K_M | 0.75 GiB | 806,058,240 | 6.449 | — | lmstudio-community |
| Q4_K_M | 0.75 GiB | 806,058,272 | 6.449 | 340 | unsloth |
| Q5_K_S | 0.78 GiB | 836,399,648 | 6.692 | — | unsloth |
| Q5_K_M | 0.79 GiB | 851,345,696 | 6.811 | 340 | unsloth |
| Q4_0 | 0.93 GiB | 1,003,541,152 | 8.029 | — | |
| Q6_K | 0.94 GiB | 1,011,738,624 | 8.095 | 340 | lmstudio-community |
| Q6_K | 0.94 GiB | 1,011,738,656 | 8.095 | 340 | unsloth |
| Q8_0 | 1.00 GiB | 1,069,306,368 | 8.555 | — | lmstudio-community |
| Q8_0 | 1.00 GiB | 1,069,306,368 | 8.555 | 340 | ggml-org |
| Q8_0 | 1.00 GiB | 1,069,306,400 | 8.555 | 340 | unsloth |
| BF16 | 1.87 GiB | 2,006,573,344 | 16.054 | — | unsloth |
| F16 | 1.87 GiB | 2,006,573,568 | 16.054 | 340 | ggml-org |
KV cache by context
| Context | KV cache (f16)● | Flat formula | Overstated by | Full / windowed / recurrent |
|---|---|---|---|---|
| 4,096 | 0.04 GiB | 0.10 GiB | 2.74× | 4 / 22 / 0 |
| 8,192 | 0.05 GiB | 0.20 GiB | 3.85× | 4 / 22 / 0 |
| 16,384 | 0.08 GiB | 0.41 GiB | 4.84× | 4 / 22 / 0 |
| 32,768 | 0.15 GiB | 0.81 GiB | 5.55× | 4 / 22 / 0 |
| 65,536 | 0.27 GiB | 1.63 GiB | 5.99× | 4 / 22 / 0 |
| 131,072 | 0.52 GiB | 3.25 GiB | 6.23× | 4 / 22 / 0 |
22 of 26 layers cache only a 512-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 0.52 GiB. The real file is 0.75 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 0.81 GiB at 32K context where the real figure is 0.15 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 gemma-3-1b-it need?
- Q4_K_M is exactly 806,058,240 bytes (0.75 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
- How large is gemma-3-1b-it's KV cache?
- 0.15 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 gemma-3-1b-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.