Download Time Calculator

Estimate how long a download takes from the file size and your connection speed, handling both megabit and megabyte units. Calculates in your browser.

Estimated download time

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Total seconds-

Show the math

Convert the file to bits, then divide by the link rate in bits per second:

time = file size × 8 ÷ speed (bits/s)

Speeds are usually quoted in megabits per second (Mbps) while files are in megabytes (MB), and one byte is eight bits, so a 100 Mbps line moves about 12.5 MB each second. Real transfers run a little slower due to overhead. Calculated entirely in your browser.

What this does

A download-time calculator estimates how long a download takes from the file size and your connection speed.

How to use it

  1. Enter the file size.
  2. Enter your connection speed.
  3. Pick Mbps or MB/s.
  4. Read the estimated time.

How it works

Mbps is an eighth of MB/s. Real downloads run a little slower because of protocol overhead, latency and congestion.

time = file size in bits ÷ speed in bits per second

Understanding your result

Real downloads run slower than this ideal because of protocol overhead, latency, congestion, and a server that may cap your speed, so treat the number as a best case. The common trap is units: a 100 Mbps connection is about 12.5 MB/s, so divide an advertised megabit speed by eight before comparing it to a file size in megabytes.

Example

A 1 GB file over 100 Mbps takes about 80 seconds.

Sources & methodology

Last updated .

Frequently asked questions

How is download time calculated?

The file size is converted to bits and divided by the connection speed in bits per second. For example, a 1 GB file over 100 Mbps takes about 80 seconds.

Why is it slower in practice?

Real downloads lose time to protocol overhead, latency, congestion and server limits, so they typically run a little slower than this best-case estimate.

Mbps or MB/s?

Connection speeds are usually quoted in megabits per second (Mbps), which is one eighth of megabytes per second (MB/s). The calculator supports both so you can match how your plan is advertised.