Result
Data Transfer Time Calculator
Estimate transfer time from file size in gigabytes and connection speed in megabits per second.
Bytes, bits and connection speed
Method and inputs
File size is entered in decimal gigabytes: 1 GB = 1,000,000,000 bytes. Speed is in megabits per second, not megabytes. Each byte contains eight bits, so seconds = GB × 8,000 ÷ Mbps.
Worked example
A 2 GB file over a 100 Mbps connection needs 2 × 8,000 ÷ 100 = 160 seconds, or 2 minutes 40 seconds under ideal conditions. At 50 Mbps the same transfer takes 320 seconds.
Limits and common mistakes
Protocol overhead, Wi-Fi interference, server limits and competing devices usually increase the time. A GiB is 1,073,741,824 bytes and must be converted to GB before entry. An advertised speed is not necessarily sustained throughput.
How do I use a speed shown in MB/s?
Multiply megabytes per second by eight to obtain Mbps. For example, 12.5 MB/s equals 100 Mbps. Keep the uppercase B for bytes and lowercase b for bits.
Content updated: 2026-10-03.