ConverterHub

Download Time Calculator

How long will this download take?

How it is calculated

The tool converts everything to bits and divides: seconds = size × 8 / speed. File size is taken in decimal units (1 MB = 1,000,000 bytes, 1 GB = 10⁹ bytes, 1 TB = 10¹² bytes) and multiplied by 8 to get bits. Speed units are Mbps (megabits per second, 10⁶ bits/s), Gbps (10⁹ bits/s) or MBps (megabytes per second, counted as 8 × 10⁶ bits/s). The seconds are then shown as hours, minutes and seconds. The result is the ideal time at a constant full speed: real transfers are slower because of protocol overhead, shared connections, server limits and Wi-Fi quality. Size and speed must be above zero.

Worked example

A 4.5 GB game download on a 100 Mbps connection. Size in bits: 4.5 × 10⁹ × 8 = 36 × 10⁹ bits. Speed: 100 × 10⁶ bits per second. Time = 36 × 10⁹ / 100 × 10⁶ = 360 seconds, which the tool shows as 6 min. If you mistakenly read 100 as megabytes per second, you would expect about 45 seconds, an eightfold difference.

Try this example →

Common mistakes

  • Mixing up megabits (Mbps, used for internet plans) and megabytes (MBps, used for file sizes); one byte is 8 bits, so the answer differs by a factor of 8.
  • Choosing the wrong unit in the dropdown, such as TB instead of GB.
  • Expecting to reach the advertised speed; real throughput is often lower than the plan's maximum.
  • Forgetting that the speed is shared between all devices on the network.
  • Using binary sizes (GiB) and expecting an exact match, since the tool uses decimal GB.

About this calculator

This calculator divides a file's size by your connection speed to estimate how long a download or upload will take, converting between the units files are measured in (megabytes, gigabytes) and the units internet speeds are advertised in (megabits, gigabits per second) — a distinction that trips a lot of people up since 1 byte equals 8 bits.

It's used to sanity-check an ISP's advertised speed against real-world transfer times, to plan around a large download like a game update, video file or OS image before starting it, and by IT staff estimating how long a backup, file transfer or software deployment will take over a given network link.

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