Results
Enter your speed and file size, then select Calculate.
- Estimated real-world time
- Theoretical time (100% of plan speed)
- Equivalent transfer speed
How it is calculated
- Internet speeds are measured in bits; file sizes in bytes. One byte is 8 bits, so a 100 Mbps connection moves at most 12.5 MB per second.
- Decimal (SI) units are used, as internet providers and storage makers do: 1 Mbps = 1,000,000 bits per second, 1 Gbps = 1,000 Mbps, 1 MB = 1,000,000 bytes, 1 GB = 1,000 MB, 1 TB = 1,000 GB.
- Theoretical time = file size in bits รท connection speed in bits per second. It is the fastest the download could possibly finish.
- Real-world time divides the theoretical time by the efficiency factor (85% by default). This allows for protocol overhead (TCP/IP, encryption), Wi-Fi losses, network congestion and other devices sharing the line.
- The estimate assumes the server can send as fast as your connection can receive. Slow or busy download servers, VPNs and distant servers can make downloads take much longer.
- Windows and some apps show sizes in binary units (1 GB shown = 1,073,741,824 bytes). A file Windows reports as 50 GB is about 53.7 GB in decimal units, so it will take roughly 7% longer than this calculator shows for "50 GB".
Examples
- A 50 GB game on a 100 Mbps connection: theoretically 1 hour 6 minutes 40 seconds; about 1 hour 18 minutes at 85% efficiency.
- A 4 GB film on a 25 Mbps connection: theoretically 21 minutes 20 seconds; about 25 minutes at 85% efficiency.
- A 1 TB backup on a 1 Gbps connection: theoretically 2 hours 13 minutes 20 seconds; about 2 hours 37 minutes at 85% efficiency.