Quick answer: Uploading 20 GB (163,840 megabits) takes about 5 h 41 min at 10 Mbps, 1 h 8 min at 50 Mbps, 34 min at 100 Mbps and 3 min at 1 Gbps, allowing 80% of the line speed for real-world overhead. The formula: size in megabits ÷ upload speed in Mbps. At this size, send it as a download link rather than through email or chat apps.
Upload time for 20 GB by connection
| Connection | Upload speed | Best case | Realistic (80% of the speed) |
|---|---|---|---|
| 4G / LTE mobile (typical; often 5 to 20 Mbps) | 10 Mbps | 4 h 33 min | 5 h 41 min |
| 5G mobile (good signal; often 20 to 100 Mbps) | 50 Mbps | 55 min | 1 h 8 min |
| Home broadband (basic cable or DSL upload) | 10 Mbps | 4 h 33 min | 5 h 41 min |
| Home broadband (common cable upload) | 20 Mbps | 2 h 17 min | 2 h 51 min |
| Home broadband | 50 Mbps | 55 min | 1 h 8 min |
| Fibre (entry-level fibre) | 100 Mbps | 27 min | 34 min |
| Fibre | 500 Mbps | 5 min | 7 min |
| Fibre (symmetric gigabit) | 1000 Mbps | 3 min | 3 min |
Mobile rows use typical upload speeds; yours can be far higher or lower depending on signal, network and time of day. Broadband rows use the upload speed of the plan, which is usually much lower than the download speed on cable and DSL.
How the time is worked out
Time in seconds = file size in megabits ÷ upload speed in megabits per second.
For 20 GB: 20 × 1,024 MB = 20,480 MB; × 8 bits per byte = 163,840 megabits. At 20 Mbps that is 163,840 ÷ 20 = 8,192 seconds, or about 2 h 17 min. Real uploads rarely hold the full speed (Wi-Fi, protocol overhead, other devices), so at 80% it is about 2 h 51 min.
Watch the units: speeds are in megabits (Mbps), file sizes in megabytes (MB), and 1 byte = 8 bits. A "20 Mbps" connection moves at most 2.5 MB per second. We count 1 GB as 1,024 MB; Macs and phones count 1,000 MB and Windows about 1,074 million bytes, a difference of under 5%.
What 20 GB of video looks like
| Video | Bitrate | Length in 20 GB |
|---|---|---|
| iPhone 1080p 30 fps (HEVC) | 8 Mbps | about 5 h 41 min |
| iPhone 4K 30 fps (HEVC) | 22.7 Mbps | about 2 h |
| iPhone 4K 60 fps (HEVC) | 53.3 Mbps | about 51 min |
| Apple ProRes 422 HQ, 4K UHD 29.97 | 707 Mbps | about 4 min |
Worked out from the bitrates on our video file size pages. So a 20 GB upload is typically a long phone video, a shoot's worth of RAW photos or a project folder.
Which apps accept a 20 GB file
Can you send a single file of this size (about 20 GB) as an attachment?
| App | Limit | Fits? |
|---|---|---|
| Gmail | 25 MB per email | No, send a link |
| Outlook.com | 20 to 25 MB per email | No, send a link |
| WhatsApp (document) | 2 GB per file | No, send a link |
| Telegram | 2 GB per file | No, send a link |
| Facebook Messenger | 100 MB per file | No, send a link |
| Discord (free) | 20 MB per file | No, send a link |
| Slack | 1 GB per file | No, send a link |
| WeTransfer (free) | 3 GB per transfer | No, send a link |
| Share Large Video Files | 20 GB per transfer | Send the link anywhere |
Limits from our file size limits by app table, checked against each service's help pages.
Tips for uploading 20 GB
- Plug the computer into the router with a cable if you can. Wi-Fi through walls often halves the real upload speed.
- Stop other uploads while it runs: cloud photo backup, OneDrive or Dropbox sync and video calls all share the same upload bandwidth.
- Stop the computer from sleeping during the upload (Windows power settings; on a Mac, System Settings > Energy or Battery) and keep the browser tab open.
- Start it before you leave the computer for a few hours, or overnight, and check the upload speed with a speed test first so you know how long to expect.
- Do not zip video or photos just to make them smaller: they are already compressed, so a ZIP saves almost nothing. Zip only to keep a folder together.
- Uploading once and sending a link is faster for several recipients than attaching the file to several messages: the file is uploaded one time only.
Frequently asked questions
How long does 20 GB take to upload on 4G?
About 5 h 41 min at a typical 10 Mbps 4G upload speed, and about 11 h 23 min if the signal only gives 5 Mbps. On 5G at 50 Mbps it is about 1 h 8 min.
How long does 20 GB take on 100 Mbps?
About 27 min at the full 100 Mbps upload speed and about 34 min in practice. Check that 100 Mbps is your upload speed, not only the download speed.
Why is my upload slower than my internet speed?
Most cable and DSL plans advertise the download speed; the upload speed is often 5 to 20 times lower. Wi-Fi, other devices on the network and the distance to the server reduce it further. Run a speed test and look at the upload figure.
Is Mbps the same as MB per second?
No. Mbps is megabits per second; 8 bits make a byte, so 100 Mbps is at most 12.5 MB per second. That is why 20 GB takes about 27 min at 100 Mbps, not 3 min.
Can I upload 20 GB for free?
Share Large Video Files takes up to 20 GB per transfer, free and without an account. If your files are larger, split them into several transfers or zip them into parts.
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