One of the questions people often want to know is how long it will take them to backup their data to Mozy. It is a difficult question to answer because there are many different variables that determines how fast your data is transferred.

One way to get an estimate of how long it will take is to visit an Internet speed test site like the Speakeasy Speed Test or my favorite Speedtest.net. This will test your download and upload speed. For backing up your data the speed you need to know is your upload speed. Your upload speed should be close to what you purchase from your ISP. It can vary slightly depending on network traffic and where you are uploading to.

Knowing what your upload speed is you can use a tool like iBeast File Size Bandwidth Calculator or T1Shopper File Transfer Time – Data Transfer Speed Calculator. I prefer the T1Shopper tool because it has my exact upload speed listed. You can enter the amount of data in MB or GB that you have to back up and it will give you a rough estimate of how long it will take to transfer it over your upload speed.

For example on my 512Kbps DSL connection the T1Shopper tool suggests it will take roughly 4 Hours 39 Minutes 37.22 Seconds to upload 1GB of data. That is a good estimate but it will usually take slightly longer since I usually do not get the full upload speed of 512Kbps from my ISP. According to Speedtest.net my upload speed is around .5Mbps which is 500Kbps so it will take me a little longer than the estimate to upload my 1GB. It gets more confusing because Speedtest reports the upload speed in Mbps and not Kbps. If you need a hand converting here is a Bandwidth conversion calculator.

It does get confusing but the good part is once your initial upload is done the regular uploads after that as pretty fast.