Running on your device · 0 bytes uploaded
Bandwidth and download-time calculator
How long a file takes at a given line rate — exact fractional seconds, decimal and binary unit bases kept separate, and no fake efficiency percentage.
exact BigInt fractions · wire time only — overhead is not modeled and not pretended
6m 43s + 1419777/1953125s
Exactly 403 + 1419777/1953125 seconds (12500000 bytes/second average at this rate).
Wire time at the stated line rate. Protocol overhead (TCP/IP/Ethernet framing), windowing, and competing traffic are NOT modeled — real transfers take longer; no fake efficiency percentage is applied.
- Decimal (SI): kB, MB, GB = powers of 1000; kbit/s, Mbit/s likewise — the units ISPs advertise.
- Binary (IEC): KiB, MiB, GiB = powers of 1024 — the units file managers show. The same number in the two bases is a different transfer; the picker states which you chose.
- Rates are bits, sizes are bytes — the factor of 8 is exact BigInt arithmetic, and fractional inputs stay exact fractions (1 MiB at 1 Mbit/s is 8.388608 s, not 8.4).
- Wire time means the line-rate ideal. TCP/IP framing, windowing, TLS handshakes, and competing traffic all add time; inventing an "efficiency" number would be lying with decimals, so the tool refuses to.
Done
Finished here in the tab. Nothing was uploaded.
exact rational arithmetic — the fraction of a second is printed, not rounded away