Work out how long a file will take to download from its size and your internet speed.
Last updated: October 31, 2026
Megabits vs megabytes
Internet speed is measured in megabits per second (Mbps), while file sizes are in megabytes (MB) or gigabytes (GB). One byte is 8 bits, so a 100 Mbps connection downloads at most 100 ÷ 8 = 12.5 MB per second. Formula: download time (seconds) = file size (MB) × 8 ÷ speed (Mbps). Example: a 50 GB game at 100 Mbps takes 50,000 × 8 ÷ 100 = 4,000 seconds, or about 1 hour 7 minutes. Real downloads usually take longer. Part of the bandwidth goes to protocol data, other devices on your network share the line, and the server may not send as fast as you can receive. The realistic row allows for about 10% overhead; on Wi-Fi the loss can be bigger. The calculator uses decimal units (1 GB = 1,000 MB), as internet providers and storage makers do. Windows shows file sizes in binary units (1 GB = 1,024 MB), so the size it shows may look a little smaller.
Common questions about download time
12.5 MB/s in theory. In practice you'll usually see 10–12 MB/s.
Other tools you may find useful
Size of the game, film or backup.
Download speed from a speed test.