How it works
Storage and network units come in two families. Decimal units (kB, MB, GB) use powers of 1000; binary units (KiB, MiB, GiB) use powers of 1024. Network speeds are almost always in bits per second, so divide by 8 to get bytes.
Transfer time here is the ideal time at the full link rate. Protocol overhead, latency and congestion typically add 10–30%, more on cellular and long-range radio links.
1 byte = 8 bits
1 MB = 1,000,000 bytes 1 MiB = 1,048,576 bytes
Time = size (bits) / link speed (bit/s)Worked example
A 250 MB firmware image is 2,000,000,000 bits. Over a 10 Mbit/s link that takes 2×10⁹ / 10⁷ = 200 seconds, about 3 minutes 20 seconds, before protocol overhead. 250 MB is also 238.4 MiB.