SavingBits

Downloads

How long does 1 TB take to download on gigabit internet?

2 h 20 min

to download 1 TB at 1 Gbps, best case. Typical: 2 h 47 min (at 80 % efficiency, our estimate for Wi-Fi and busy servers).

Gigabit means 1,000 megabits per second, or 125 megabytes per second at most. Wi-Fi and the far server rarely keep that up for a whole terabyte, so look at the typical row.

The arithmetic

  1. 1,000 GB × 8 bits per byte = 8,000 gigabits (8,000,000,000,000 bits)
  2. 1,000 Mbps = 1,000,000,000 bits per second = 125 MB/s at most
  3. 8,000,000,000,000 ÷ 1,000,000,000 = 8,000 s = 2 h 13 min with zero overhead
  4. TCP/IP and Ethernet framing use about 5 % of the line (1,460 data bytes per 1,538 on the wire): 8,000 ÷ 0.949 = 2 h 20 min

If the size is really 1,000 GiB (some stores and Windows label GiB as GB), it is 7.4 % bigger: 2 h 31 min best case.

1,000 GB at other speeds
SpeedBest case (95 %)Typical (80 %, estimate)
10 Mbps9 days 18 h11 days 14 h
25 Mbps3 days 22 h4 days 15 h
50 Mbps46 h 49 min2 days 8 h
100 Mbps23 h 25 min27 h 47 min
300 Mbps7 h 48 min9 h 16 min
500 Mbps4 h 41 min5 h 33 min
1,000 Mbps2 h 20 min2 h 47 min

Sources and assumptions

  • Overhead: 94.9 % efficiency from TCP/IPv4 on 1,500-byte Ethernet frames (computed); 80 % 'typical' is our estimate.

Try your own numbers in the download time calculator