Calculator / Network
Download Time Calculator
Estimate a file download from its size and your stated connection speed. See the raw line-rate time beside a practical 85%-efficiency estimate.
How the time is calculated
Connection speeds are stated in bits per second, while file sizes are usually shown in bytes. The calculator converts the file to bits, divides by the chosen line rate, then applies the optional efficiency allowance.
estimated seconds = theoretical seconds ÷ 0.85
Why an actual download can take longer
Protocol overhead, Wi-Fi quality, congestion, server limits and other traffic can all reduce usable throughput. For example, a 1 GB decimal file contains 8,000,000,000 bits. At 100 Mbps its line-rate time is 80 seconds; at 85% efficiency the estimate is about 94.1 seconds.
Units used here
KB, MB, GB and TB use decimal multiples of 1,000. Connection units use Kbps, Mbps and Gbps, also based on 1,000.