How long does it take to download Llama 3.1 8B?

The most common quant, Q4_K_M, is 4.92 GB. On a 30 Mbps Sri Lankan fibre line at 85% efficiency that is about 26 minutes. On a 100 Mbps line it drops to roughly 7 minutes. The full 70B model at Q4_K_M is 42.52 GB — closer to an hour on 100 Mbps.

How big is a Q4_K_M GGUF model file?

It depends on parameter count. Q4_K_M is about 0.6 GB per billion parameters: Llama 3.2 1B is 0.81 GB, Llama 3.1 8B is 4.92 GB, Qwen2.5 14B is 8.99 GB, and Llama 3.1 70B is 42.52 GB. Q4_K_M is the popular default because it keeps most of the quality at roughly half the full-precision size.

How do I convert Mbps to download time?

Divide the file size by the speed, keeping the units consistent. In decimal units: time in seconds = size in GB × 8000 ÷ (speed in Mbps × efficiency). The ×8000 converts GB to megabits (×8 bits, ×1000 GB→Mb). Efficiency (0.30–1.0) accounts for overhead and throttling. This tool does that arithmetic for you.

How much data does downloading an LLM use?

Exactly the file size — a 4.92 GB model uses 4.92 GB of your data allowance, plus a negligible amount of protocol overhead. There is no hidden multiplier. If you re-pull the same model after clearing it, it downloads again in full unless your tool resumes a partial file.

Is Sri Lankan broadband fast enough to run local AI models?

Yes for the download — the bottleneck is your GPU/RAM, not the line. A 30 Mbps SLT fibre plan pulls an 8B model in under half an hour and a 3B model in a few minutes. Larger 70B models take longer and eat 40 GB+, so check your data cap first with the calculator above.

Why is my real download slower than the estimate?

Advertised line speeds are peak, not sustained. Hugging Face may rate-limit, your Wi-Fi or a shared line adds contention, and TCP/HTTPS carries overhead. That is what the efficiency slider models — lower it to 60–70% for a busy evening connection to get a more realistic figure.

What is the difference between GGUF quants and full weights?

Full weights (FP16) store each parameter in 2 bytes — an 8B model is about 16 GB. GGUF quantization compresses them: Q8_0 keeps ~1 byte/param, Q4_K_M about half a byte, Q2_K less. Smaller quants download faster and use less disk and RAM, at a small quality cost. FP16 rows here are estimated as params × 2 bytes.

Does the estimate include resuming or multiple connections?

No. It assumes one sequential stream from start to finish. Download accelerators, mirrors, or resuming a partial file can change the real time. Ollama and llama.cpp pull single-threaded by default, which is what this models. Treat the number as a realistic single-stream estimate, not a guaranteed floor.

AI · Local LLMs

AI Model Download Time Calculator

Estimate how long a local AI model — an LLM GGUF quant or full-precision weights — takes to download at your internet speed, and how much data it burns. Pick a popular model, set your speed, and see the time in seconds. No signup, sizes from Hugging Face, sources cited below.

By Induwara Ashinsana— Executive Director, Ryzera TechnologiesUpdated Jul 18, 2026

Model download timeGGUF & full weights

HF sizes verified · 2026

Model & quantization

Llama 3.1 8B Instruct · Q4_K_M · 4.92 GB

Connection speed (Mbps)

Mbps

Your line's download speed in megabits/s (max 10,000).

Speed presets

Real-world efficiency85%

Drag from 30% (busy shared line) to 100% (ideal, uncontended).

Estimated time

25 min 44 s

Data used

4.92 GB

Equals the file size

Effective speed

3.19 MB/s

After efficiency discount

Download size

Q4_K_M · 4.92 GB

Time by connection speed

Connection speed	Estimated time
10 Mbps	1 h 17 min 11 s
20 Mbps	38 min 35 s
30 Mbpsyour speed	25 min 44 s
50 Mbps	15 min 26 s
100 Mbps	7 min 43 s
500 Mbps	1 min 33 s

Assumes one sequential stream. Data used equals the file size; time scales linearly with size. Sizes from Hugging Face GGUF cards (bartowski), units per Ookla/ISP convention (1 GB = 10⁹ bytes, 1 Mbps = 10⁶ bit/s). Verified 2026-07-18.

How it works

Download time is a units problem: divide the file size by the speed, keeping the units consistent. Internet speed is quoted in megabits per second (Mbps), but files are measured in gigabytes (GB) — and there are 8 bits in a byte — so the two need converting before they divide cleanly. This tool follows the decimal convention that ISPs and Ookla's Speedtest use: 1 GB = 10⁹ bytes and 1 Mbps = 10⁶ bits per second.

The calculation runs entirely in your browser:

Take the model file size in GB — from the selected preset (a real Hugging Face GGUF file size) or your custom input.
Convert to bits: bits = sizeGB × 10⁹ × 8.
Convert your line speed to bits per second and apply a real-world efficiency factor e (0.30–1.0) for TCP/HTTP overhead, server-side throttling and shared-line contention: bit/s = speedMbps × 10⁶ × e.
Divide. The 10⁹ and 10⁶ cancel to a clean form:
seconds = (sizeGB × 8000) ÷ (speedMbps × e)
Format the seconds into hours, minutes and seconds. Data used equals the file size, because a download transfers exactly the file (protocol overhead is a fraction of a percent).

The result is cross-checked against the "megabytes per second" path your download manager actually displays: MB/s = speedMbps × e ÷ 8, then seconds = sizeMB ÷ MB/s. Both methods agree to the second. Preset sizes are the exact on-disk figures published on the bartowski GGUF model cards on Hugging Face; full-precision (FP16) rows are estimated as params × 2 bytes and marked with a ≈ sign. Time scales linearly with size and inversely with speed: double the Mbps and the wait halves.

Worked examples

Llama 3.1 8B, Q4_K_M — 30 Mbps SL fibre

4.92 GB · 30 Mbps · 85% efficiency

Size in megabits: 4.92 × 8000 = 39,360 Mb
Effective speed: 30 × 0.85 = 25.5 Mbps
Time: 39,360 ÷ 25.5 = 1,543.5 s
1,543.5 s → 25 min 44 s
Data used: 4.92 GB

Llama 3.1 70B, Q4_K_M — 100 Mbps fibre

42.52 GB · 100 Mbps · 90% efficiency

Size in megabits: 42.52 × 8000 = 340,160 Mb
Effective speed: 100 × 0.90 = 90 Mbps
Time: 340,160 ÷ 90 = 3,779.6 s
3,779.6 s → 1 h 3 min 0 s
Data used: 42.52 GB — check it against your data cap

Edge case — Llama 3.2 1B on mobile data

0.81 GB · 20 Mbps 4G · 60% efficiency (busy line)

Size in megabits: 0.81 × 8000 = 6,480 Mb
Effective speed: 20 × 0.60 = 12 Mbps
Time: 6,480 ÷ 12 = 540 s
540 s → 9 min 0 s
A tiny model still finishes fast even on a congested 4G line.

Frequently asked questions

Sources & references

Preset file sizes and the Sri Lanka speed seeds were last cross-checked against the Hugging Face model cards and the Ookla index on 2026-07-18. The Mbps and size fields are fully editable, so the calculation is never tied to a stale preset.

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Comments & feedback

Spotted a bug or want an improvement? Tell us — our team reviews every comment, and good ideas get built. Comments are public and anonymous.

Found a bug, a wrong file size, or want another model added?

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