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i'm using to measure my internet speed. And here it is:

Download Speed: 422 kbps (52.8 KB/sec transfer rate)
Upload Speed: 202 kbps (25.3 KB/sec transfer rate)

Can you please explain to me how did they get the 52.8 transfer rate. And how do I get to lower the upload speed in order for me to get higher download speed.

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up vote 4 down vote accepted

Download speed is determined by the website downloading a file of a known size from a server to your computer, measuring the amount of time it took to download. So, for example, if the webapp downloaded a 100KB file in 2 seconds, you would have a download speed of 50KB/sec (100/2 = 50).

Upload speed is determined the same way - a file (I would assume the same file it downloaded) is uploaded from your computer to the server, and the webapp measures the time it took to upload the file and calculates the speed.

As for your speeds, it varies by ISP, your purchased package, and even internet congestion. Mine, for example, showed:

Download Speed: 13905 kbps (1738.1 KB/sec transfer rate)
Upload Speed: 2416 kbps (302 KB/sec transfer rate)

Your maximum speeds, both up and down, are usually set by your ISP and isn't something you can adjust. The reason that your download speed is higher (usually very much so) is that most of what you do on the internet involves far more downloading (especially if we're talking about watching videos/playing games!) than uploading. has some tools that you might be able to use:

  • Tweak Test: "Tests if your computer is setup correctly for broadband TCP connectivity. Your PC may not be tuned properly to take full advantage your full connection speed. For those with high speed connections (faster cable networks, FiOS, etc), tuning your TCP stack is necessary if you wish to fully utilise the available bandwidth in one single download."

    • Be careful if you're running a newer OS like Windows Vista or Windows 7 - the TCP stack doesn't take well to being messed with.

  • Line Quality Testing:: "Packet loss tests on your line, including identification of any problem routers en-route to you. If you are HAVING TROUBLE with your broadband connection, and it relates to packet loss, excessive latency, or internet or ISP congestion, this test may help find the cause."

You can also take a look at DSLReport's FAQ on Broadband technology.

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Transfer speeds measured by most web sites have to be taken with a huge dose of skepticism. (File size / transfer time) would be the right way to present file-transfer speeds. Unfortunately, I haven't found a site yet that does that. If you watch the speed meter they present, you'll see that they will quote you the maximum speed the meter ever reached, even though it may have peaked only once and for only a tiny fraction of the time taken. Timing it yourself with a wristwatch (assuming you can find out the file size) would give far more representative results. – JRobert Nov 7 '10 at 17:05

I assume you have an ADSL or ADSL2+ connection?

As you can see on Wikipedia#ADSL, the frequency band for download is larger than the one for upload (and thus the data bandwidth). This is reflects the expected behaviour of most users who download much more content than they upload.

The lower than theoretical maximum speed is most liekly due to slow connection of your ISP to or due to a bad physical line from your phone socket to your ISP (either in your house, or on the phone line to the exchange).

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To get 52.8 KB/sec, divide 422 kilobits/sec by 8 (8 bits to a byte). The test got 422 kbps by downloading a file of a known size and timing how long it took (size / time will give you bandwidth speed).

Measuring bandwidth can be tricky, so you should usually run tests several times and from several different sites. Take the average or what seems to be the most common speed of the various tests.

Finally, you cannot trade upload speed for more download speed. Those are independent numbers. The maximum value for each is determined by your Internet provider based on the technology they use and the plan you pay for.

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so can I request them to trade the upload speed for download? – Ieyasu Sawada Apr 15 '10 at 4:17
No you can't. Your provider will have various packages for various monthly costs. You pick the package you want and pay that cost. – kbyrd Apr 15 '10 at 14:01

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