Transfer time calculator

Enter how much data you are moving and how fast the connection is. It tells you how long the copy takes, with the protocol overhead real transfers lose, and compares common port speeds.

Transfer time 14m 49s 100 GB at 1 Gbit/s, after 10% overhead.
Effective speed
112.5 MB/s
Data per hour
405 GB
Data per day
9.72 TB

The same amount at other speeds

100 Mbit/s
2h 28m
1 Gbit/s
14m 49s
10 Gbit/s
1m 29s

Moving a lot of data every month? Servers with unmetered traffic never bill you for the extra terabytes. From €4.48 a month today, among 479 servers.

Servers with unmetered traffic Bandwidth calculator

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How it is calculated

Sizes are counted in bytes and line speeds in bits, and one byte is eight bits. Divide the bits to move by the speed that is left after overhead:

time = size × 8 ÷ (speed × (1 − overhead))

The calculator uses decimal units, as providers and network cards do: 1 GB = 1,000 MB and 1 Gbit/s = 1,000 Mbit/s. The slower end of the path sets the pace, so a 10 Gbit/s server sending to a 100 Mbit/s home line copies at about 100 Mbit/s, and a single disk or a busy CPU can be the limit too.

Example

100 GB at 1 Gbit/s with 10% overhead: 100 × 8,000 Mbit ÷ (1,000 Mbit/s × 0.9) = 889 seconds, about 14 minutes 49 seconds.

Questions

How long does it take to download 1 TB at 1 Gbit/s?

About 2 hours 13 minutes in theory (8,000,000 Mbit ÷ 1,000 Mbit/s = 8,000 seconds), and close to 2 hours 28 minutes with 10% overhead. At 100 Mbit/s the same terabyte takes about 22 hours, or nearly 25 with overhead.

What is the difference between Mbit/s and MB/s?

Mbit/s (megabits per second) is how connections and server ports are sold; MB/s (megabytes per second) is what download windows show. One byte is eight bits, so 1 Gbit/s is at most 125 MB/s and 100 Mbit/s is at most 12.5 MB/s.

Why is my transfer slower than my connection?

Protocol overhead takes 5–10%, and the slowest part of the path decides the rest: the other end’s port, a congested route, the distance (one TCP stream slows down with latency), a slow disk or encryption on a small CPU. Copying with several parallel streams often gets closer to the line speed.

Does transfer time count against my server’s traffic?

Usually outgoing traffic counts against the monthly allowance and incoming traffic is free, but providers differ. Moving a whole server out can use several terabytes, so check the allowance and the price per extra TB before you start.