Download time calculator

How the download time is calculated

Download time is size divided by rate, once both are in the same units. File sizes are in bytes and speeds in bits, so the calculator converts the size to bits first:

seconds = size in GB × 8,000 ÷ speed in Mbps

The 8,000 comes from 8 bits per byte and 1,000 megabits per gigabit. With the real-world efficiency box ticked, the speed is multiplied by the efficiency first (90% by default, editable), so the estimate allows for protocol overhead and small slowdowns:

seconds = size in GB × 8,000 ÷ (speed in Mbps × efficiency)

The result is shown as a readable duration and as totals in seconds, minutes and hours. Below it, a table times the same file at 10, 25, 50, 100, 300, 500 and 1,000 Mbps, so you can see what a faster plan would change.

Worked examples

• A 50 GB game on 300 Mbps. 50 × 8,000 ÷ 300 = 1,333 seconds, or 22 minutes 13 seconds at full speed. At 90% efficiency it is about 24 minutes 41 seconds.
• A 10 GB update on 100 Mbps. 800 seconds, which is 13 minutes 20 seconds. On a 25 Mbps line the same update takes 53 minutes 20 seconds; on 1,000 Mbps, 80 seconds.
• A 1 GB video on 50 Mbps. 160 seconds, or 2 minutes 40 seconds.

Detailed walk-throughs for the two most common sizes are in how long to download 1 GB and how long to download 10 GB.

Why real downloads take longer

The plain formula assumes the whole plan speed goes to one file. In practice several things take a share:

• Protocol overhead. Packet headers use part of every transfer. On wired gigabit, speed tests typically peak around 940 Mbps rather than 1,000.
• The server. Game stores, cloud drives and websites often send each download at less than your plan speed, especially at busy times.
• Wi-Fi and other devices. Distance from the router and other people streaming at the same time both reduce what one download gets.
• Storage. Game launchers also unpack and write files, which can make the last part of a download slower than the network.

If a download is much slower than the estimate, check what it shows in MB/s and convert it with Mbps to MB/s to see what share of the plan you are getting.

Tips

Match the size unit to the source: game stores and operating systems sometimes show GiB, which is 7.4% larger than a GB. Use the size presets (1, 5, 10, 50 and 100 GB) for quick comparisons. For sending files rather than receiving them, use the upload time calculator, since upload speeds are usually lower; for copies over USB, Ethernet or Thunderbolt, the file transfer time calculator has connection presets.