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Transfer time

Decimal GB; 8 bits per byte. Efficiency includes overhead. Disk limits and variable latency are excluded.

Quick answer · example

How long does transferring 100 GB take?

Transferring 100 GB at 100 Mbps with 80% efficiency takes 10,000 seconds: 2 h 46 min 40 s. This assumes decimal units and constant speed without interruptions.

Calculation assumptions

Decimal GB; 8 bits per byte. Efficiency includes overhead. Disk limits and variable latency are excluded.

View the worked example ↓

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Result

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Formula and assumptions

seconds = GB×10^9×8 / (Mbps×10^6×efficiency/100)

Decimal GB; 8 bits per byte. Efficiency includes overhead. Disk limits and variable latency are excluded.

All amounts use the same currency of your choice. These are estimates, not measurements or offers.

How to use this calculator

Estimate data transport at constant speed and efficiency. Use decimal GB and Mbps, not MB/s. Speed must reflect the whole path: a fast link cannot eliminate a slow disk or destination.

Worked example

  1. 100 GB represents 100 × 10⁹ × 8 bits.
  2. A 100 Mbps link at 80 % efficiency gives 80 Mbps useful throughput.
  3. 800 × 10⁹ / (80 × 10⁶) = 10,000 seconds: 2 h 46 min 40 s.

Example result

Time (seconds)
10,000

Interpreting the result

Refine efficiency with a representative transfer trial. Outages, retries and variable load are not simulated. Reserve additional migration time for validation and a rollback plan.

Frequently asked questions

Why are Mbps and MB/s different?

b means bits and B means bytes. Eight bits make one byte; 100 Mbps is nominally 12.5 MB/s.

What does efficiency represent?

The share of nominal speed carrying the intended data, including your allowance for overhead.

Can I enter GiB?

Convert GiB to GB first by multiplying by 2³⁰ / 10⁹, or use the software’s decimal size.

References and method

NIST — bits / bytes · References and method