# How to Calculate Data Transfer Time

The time a computer takes to transfer data is simple to calculate, and having an idea of it can be very helpful in determining whether a transfer can be completed quickly or whether it is something that should be allowed to run while the computer is not needed. All you need is the size of the file and the speed at which the data can be copied.

### Things You'll Need

• Computer
• Calculator

#### Step 1

Find the file on the computer. Right-click it and select "Properties." Record the file size. For example, the size might be 500MB.

#### Step 2

Determine the speed at which the data will be transferred. For example, a USB 2.0 device can theoretically transfer data at 480 megabits per second, although in practice it tends to be slower.

#### Step 3

Convert the file size unit to the transfer rate unit, if necessary. One megabyte equals 4 megabits, so a 500 megabyte file is 4,000 megabits.

#### Step 4

Divide the total file size by the data transfer speed. In this example, divide 4,000 (Mb) by 480 (Mbps) and you get 8.33 seconds. This is the shortest amount of time the transfer can take.

### Tips & Warnings

• Depending on how many other programs and processes are running on the computer, the transfer will not occur at maximum speed.
• When recording the size and transfer speed, pay attention to the units. Don't mistake megabytes for gigabytes.