Download Time Calculator

How it works

First convert the file size to bytes. A decimal GB contains 1,000,000,000 bytes; a binary GiB contains 1,073,741,824 bytes. Multiply bytes by eight to get bits. Divide by the effective download rate in bits per second. Here, Mbps means megabits per second, with one megabit equal to one million bits.

The efficiency setting reduces the advertised speed to allow for real-world conditions. The default 90% is an editable assumption, not a measured property of your connection. Wi-Fi interference, shared bandwidth, server limits, congestion and pauses can all make a transfer slower. A very small file may take longer than the estimate because connection setup has a fixed cost.

Choose the unit actually shown by the download source. Mixing GB and GiB changes the answer by roughly 7.4%. If a launcher shows MB/s rather than Mbps, multiply its decimal MB/s value by eight before entering it. The calculator makes no network request and does not measure your line.

A worked example

For 1 GB at 100 Mbps with 90% efficiency: 1,000,000,000 × 8 ÷ 90,000,000 = 88.89 seconds. For 1 GiB under the same conditions, the estimate is 95.44 seconds.

Common questions