Turn a file size and a copy speed into minutes. Use the megabytes per second your computer shows while copying. A cable marked 10 Gbps or 40 Gbps is a ceiling, and most copies run slower than that ceiling.
File transfer time calculator
The result updates from the fields above. This form does not store the numbers you enter.
What the result means
Minutes is how long a steady copy at that speed would take. A transfer that starts fast and then slows down, or one that pauses on many tiny files, will take longer than this single speed. Large video files are closer to the estimate than a folder of thousands of small documents.
Formula and example
Seconds = (gigabytes × 1024) ÷ MB/s. 50 GB at 100 MB/s is 51,200 ÷ 100 = 512 seconds, which is 8.53 minutes. A typical USB 3 hard drive often sits nearer 80 to 120 MB/s. A fast external SSD on USB 3.2 can be several hundred MB/s. Gigabit Ethernet is about 110 MB/s when the link is actually full.
What this number cannot tell you
The calculator does not test your cable, port, or drive. If the copy dialog never shows a speed, do not invent one from the port name. Wi-Fi, a busy drive, and antivirus scans all change the number while the copy is running.
Questions people ask
Why is my USB-C copy slower than the cable rating?
The port, the drive, and the files all have their own limits. A 10 Gbps port does not make a spinning hard drive faster than the drive itself.
Are MB/s and Mbps the same?
No. This calculator uses megabytes per second, the unit in most copy dialogs. Megabits per second, used for internet plans, are eight times smaller. A 100 Mbps internet plan is about 12.5 MB/s at best.
Does this include the time to verify the copy?
No. It is only the time to move the bytes at a constant speed.
