Model Download Time Calculator
Time the weights — parameters × bytes per parameter ÷ your bandwidth, before the first token.
Model Download Time Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Weights only — tokenizers and runtimes are megabytes
- Clean-TCP clock — no resumption or mirror variance
In short: 7 B parameters at 2 bytes a parameter (FP16, the training-precision default) weigh 14 GB — 2 min 20 s at 800 Mbps. Quantization halves the weights, twice: the same model at 4-bit reads 3.5 GB and a 70 B giant at 4-bit reads 35 GB, 5 min 50 s on the same wire. The download is the price of admission to local inference.
Formula
GB = parameters × bytes per parameter; seconds = GB × 8,000 ÷ Mbps
Model weights are parameters times the precision's bytes: FP32 stores 4, FP16/BF16 — the training default — stores 2, INT8 stores about 1, and 4-bit quantization about 0.5. The wire law is the site's decimal/SI convention: gigabytes × 8,000 ÷ megabits per second. A 7 B model at FP16 is 14 GB; the same model at 4-bit is 3.5 GB; a 70 B model at 4-bit is 35 GB — quantization is what makes local inference a consumer activity at all.
Worked Example
- Enter the parameter count and the precision you will actually run.
- Enter your measured bandwidth — not the plan's headline.
- Read the size, the clock, and what one precision step saves.
Defaults: 14 GB, 2 min 20 s at 800 Mbps. Drive to a 70 B model at 4-bit on a 50 Mbps line and the clock reads 1 h 33 min — the weights, not the license, are what gates local inference.
Strengths & Limits Of This Model
Where this engine is strong
- Size derived from the architecture, not guessed
- Precision ladder priced step by step
Where it stops
- Quantization formats vary around the half-byte line
Practical Use Cases
Local setup planning
which model fits the pipe
Precision choice
what one quantization step saves
Fleet provisioning
mirroring weights to N machines
Methodology & Editorial Standards
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Model Download Time Calculator — 8 Expert FAQs
8 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How big is a 7B model, really?
The file on disk: 14 GB at FP16, about 7 at INT8, 3.5–4 GB at 4-bit quantization. Marketing sheets quote the parameter count; your disk and your wire meet the bytes, and the bytes are parameters times precision.
Why does precision change the size so much?
Because each parameter is just a number stored at a chosen width: 4 bytes at FP32, 2 at FP16/BF16, about 1 at INT8, about 0.5 at 4-bit. Halving the width halves the weights — and a good 4-bit quantization keeps most of the quality, which is why it is the local-inference default.
Does quantization really halve the weights twice?
From the training default it does: FP16's 2 bytes halve to INT8's 1, then halve again to 4-bit's 0.5. Against FP32 it is an 8× cut. The ladder on the page prices each step; quality is a different ledger.
Why does the page ask for measured bandwidth?
Because the plan headline lies by construction — it is shared, asymmetric and best-case. Run one speed test at the hour you will actually download and enter that; the clock is only as honest as the bandwidth.
How is this different from the download time page?
That page prices any file whose size you already know; this page derives the size from the architecture — parameters and precision — and then applies the same wire law. Size known: that page. Size unknown: this one.
What about download resumption and mirrors?
The clock assumes one clean TCP run at your measured rate. Hugging Face-class mirrors usually saturate domestic broadband; hotel Wi-Fi does neither. Schedule the big pulls for the wire you trust.
Why 800 Mbps as the default?
It is a honest mid-range fiber line — fast enough that a 7 B model is a coffee break (2 min 20 s) but slow enough that a 405 B giant at FP16 (810 GB) is a weekend. The presets bracket the real wires.
Do I download the weights at all with APIs?
No — that is the API's whole deal: the token page prices renting the model by the token, weights stay home, and the wire only carries your prompts. The download is the price of owning the run.