Internet Download/Upload Time Calculator

File Size (bits) = File Size × Unit-to-Bytes × 8
Connection Speed (bits/sec) = Speed in Mbps × 1,000,000
Download Time (seconds) = File Size (bits) ÷ Connection Speed (bits/sec)

File sizes are measured in bytes (KB, MB, GB, TB); connection speeds are sold in bits per second (Mbps). Since 1 byte = 8 bits, an 8 Mbps connection moves 1 MB per second, not 8 MB — this calculator converts both sides to the same unit (bits) before dividing, so you never have to do that conversion by hand.

Step by step

How the calculation works

1. 1Enter the file size and choose its unit — kilobytes, megabytes, gigabytes, or terabytes.
2. 2Enter your connection speed exactly as it's advertised or measured — most home and mobile plans are sold in Mbps (megabits per second). If you have a measured throughput in MB/s (megabytes per second) instead, from a download manager or file transfer tool, switch the speed unit to match.
3. 3This calculator uses decimal units throughout (1 GB = 1,000 MB = 1,000,000,000 bytes), matching how connection speeds are marketed and how most download-time calculators define file size — some operating systems instead display on-disk file size using binary units (1 GiB = 1,024 MiB) but label it "GB," which can make a file look a few percent larger or smaller than this calculator's figure.
4. 4The result is a theoretical best case at your entered speed sustained for the whole download. Real downloads are usually slower due to network overhead, Wi-Fi conditions, server-side rate limits, and other traffic sharing the connection.

Related guides

Learn more about this calculation