Download time calculator
Enter a file size and a connection speed to see how long the transfer will take.
Estimated time
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How the calculation works
File sizes are measured in bytes, but internet speeds are sold in bits per second. One byte is eight bits, so the calculator multiplies the file size by eight and divides by the speed:
time (seconds) = file size (bytes) × 8 ÷ speed (bits per second)
We use decimal units (1 GB = 1,000,000,000 bytes), as storage makers and most apps do. Some operating systems show sizes in binary units (1 GiB = 1,073,741,824 bytes), so a "1 GB" file in those systems is about 7% larger.
If you enter a speed from a SpeedCheckWeb test, no overhead adjustment is needed: the test already measures the data that actually arrived. If you enter your plan's advertised speed, tick the overhead box. Real transfers can also be slower if the server is busy or other devices share the connection.