The short answer
At a sustained 100 Mbps, 1 decimal GB takes 80 seconds to transfer before overhead. At 80% effective throughput it takes 100 seconds. Use upload speed for an upload and download speed for a download; they can differ.
Calculate from bytes to seconds
Multiply file bytes by eight to get bits. Divide by bits per second. For 100 GB at an effective 80 Mbps, 800,000,000,000 bits divided by 80,000,000 bits per second gives 10,000 seconds: about 2 hours 47 minutes. It is an estimate, not a measured service result.
Account for the working environment
Shared connections, Wi-Fi, many small files and changing source or destination performance can affect elapsed time. Choose a conservative effective-throughput assumption based on a sample transfer. Do not promise a completion time using only the number printed on an internet plan.
Check the result after transfer
A completed progress bar is one signal. Open representative downloads and, when appropriate, compare checksums with known originals. Keep the source until the destination has been checked and your recovery plan is ready.
Checklist
- 1Use the correct transfer direction.
- 2Convert the collection to bytes.
- 3Choose a realistic throughput assumption.
- 4Verify a sample at the destination.
Good questions. Clear answers.
How long does 1 GB take at 10 Mbps?
At 100% effective throughput, 800 seconds, or 13 minutes 20 seconds. At 80%, 1,000 seconds.
Does the calculator promise actual upload speed?
No. It calculates duration from your entered speed and throughput assumption.
Related free tools
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