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Internet Speed Explained

Read a speed test and learn how much speed your home needs.

Reading a speed test

Internet speed is how much data can move each second. Data is everything your devices send and receive, like videos, photos and web pages.

Speed is usually measured in Mbps, or megabits per second. A bit is the tiniest piece of data, and a megabit is a million bits. Fast plans may say Gbps, gigabits per second. One Gbps is 1,000 Mbps.

A speed test is a free website or app that measures your connection. It shows three numbers:

• Download is how fast data comes to you. Streaming, browsing and opening apps use it.
• Upload is how fast data leaves you. Video calls and sending big files use it.
• Ping is how long a tiny message takes to go out and come back, in milliseconds, or ms. Lower is better. It matters most for games and calls.

Here is a common trap. File sizes use MB, megabytes, with a capital B. One byte is 8 bits. So divide Mbps by 8 to get MB per second. A 240 Mbps connection downloads about 30 MB each second.

A test only measures the path to the device you test on. A bottleneck is the slowest part of that path. Weak Wi-Fi is often the bottleneck, so a result can be far below your plan even when the ISP is fine. Testing with a cable shows what really reaches your home.

On the practice computer, run the speed test and read all three numbers. Try the converter, then test again over weak Wi-Fi and compare.

How much speed do you need?

ISPs love to sell bigger plans. But extra speed only helps if your home actually uses it.

Here are rough amounts for one activity at a time:

• Email, web pages and music: a few Mbps.
• A video call: about 2 to 4 Mbps, both down and up.
• HD video streaming: about 5 Mbps.
• 4K streaming, the sharpest picture on most TVs: 15 Mbps or more.
• Online games: little speed, but a low ping, ideally under 50 ms.

Now add up what happens at the same time. Two 4K TVs, a video call and a few phones can use 50 Mbps or more together. For most families, 100 to 300 Mbps download is plenty. In the US, the FCC treats 100 Mbps download and 20 Mbps upload as the bar for good home internet.

Upload matters more than people think. If someone works from home, sends big files or backs up photos online, check the upload number too. Cable plans often have far less upload than download.

To test fairly, pause streaming and big downloads first. Run the test two or three times, because results change a little each time. Over a cable, your result should be close to your plan. A little lower is normal.

If your wired result is fine but rooms feel slow, a faster plan won't help. Better Wi-Fi will.