Internet speed is measured in megabits per second (Mbps), which tells you how much data your connection can move in one second
When you run a speed test, you are measuring the rate at which data travels from a server to your device and back. The result — usually shown as a number like 50 Mbps or 100 Mbps — represents megabits, not megabytes. A megabit is one-eighth the size of a megabyte, which is why the number looks larger than you might expect when you download a file.
Speed tests measure three separate things: download speed (data coming to you), upload speed (data going out), and ping or latency (how long it takes for a signal to make the round trip). Most people focus on download speed because that is what affects streaming, browsing, and video calls. Upload speed matters if you work from home, stream video, or back up files to the cloud. Ping matters for online gaming and video calls where delay becomes noticeable.
Key Takeaways
- Download speed, upload speed, and ping are three separate measurements, and your internet plan usually lists only the download number.
- Speed tests like Speedtest.net or Fast.com measure your actual connection at one moment in time, not your plan's promised speed.
- Your measured speed will often be lower than your plan speed because of network congestion, distance from the server, and interference on wireless connections.
- Mbps (megabits per second) is different from MB/s (megabytes per second) — divide Mbps by 8 to see how many megabytes per second you can actually download.
Download speed, upload speed, and ping measure different things
Download speed is how fast data reaches your device. This is the number your internet provider advertises — "100 Mbps" usually means 100 Mbps download. It determines how quickly web pages load, how fast videos buffer, and whether multiple people can stream at once without lag.
Upload speed is how fast data leaves your device to reach the internet. Most home plans have upload speeds one-tenth the download speed or lower. You notice upload speed when you video call, upload photos to cloud storage, or send large email attachments. Video calls need at least 2.5 Mbps upload to work smoothly; streaming your own video to Twitch or YouTube needs 5 to 10 Mbps depending on quality.
Ping or latency is measured in milliseconds (ms) and tells you how long a signal takes to travel from your device to a server and back. Lower ping is better — 20 ms is excellent, 50 ms is good, 100 ms is noticeable in video calls, and 150 ms or higher makes online games feel sluggish. Ping depends on your distance from the server and the path your data takes, not on your speed plan.
Speed tests measure your connection right now, not your plan speed
When you run a speed test on Speedtest.net, Fast.com, or your provider's own test tool, you are measuring what your connection can actually do at that exact moment. The result is almost always lower than the speed your plan promises. This is normal and expected.
Your plan speed is the maximum your connection can theoretically reach under ideal conditions. Your measured speed is what you get in real life, affected by network congestion, how far you are from the server you are testing to, whether you are using WiFi or ethernet, and interference from other devices. If your plan is 100 Mbps and you measure 75 Mbps, that is typical. If you consistently measure 30 Mbps or lower on a 100 Mbps plan, something is wrong — either your equipment, your WiFi signal, or your provider's network in your area.
Run speed tests at different times of day to see the pattern. Most connections are slowest in the evening when everyone is home and using the internet. If you measure 90 Mbps at 2 p.m. and 40 Mbps at 8 p.m., that is congestion, not a problem with your service.
Mbps and MB/s are not the same thing
Internet speed is always measured in megabits per second (Mbps). File sizes and download speeds are usually shown in megabytes per second (MB/s). One megabyte equals 8 megabits, so to convert your speed test result to the number you see when downloading a file, divide by 8.
If your speed test shows 100 Mbps, you can download at roughly 12.5 MB/s. A 1 GB file would take about 80 seconds. This is why a 100 Mbps connection does not feel like it downloads files at 100 units per second — it does not. The units are different. Your browser or download manager shows MB/s because that is what matters for file size, but your internet plan is always sold in Mbps.
WiFi speed is usually lower than wired speed on the same plan
If you run a speed test on WiFi and then plug an ethernet cable directly into your modem, the ethernet result will almost always be higher. This is because WiFi has to share bandwidth among all your devices, and the signal weakens with distance and obstacles like walls.
The closer you are to your router and the fewer obstacles between you and it, the faster your WiFi will be. If you are in the next room with a wall between you and the router, you might measure 20 to 30 percent lower speed than ethernet. If you are far away or in a different part of the house, the drop can be 50 percent or more. This does not mean your plan is slow — it means WiFi is slower than a direct connection, which is expected.
If WiFi speed is much lower than you need, move closer to the router, reduce obstacles, or consider a WiFi 6 router if your current one is more than five years old. Older routers have lower maximum speeds even on fast plans.
What your speed test result actually tells you
A speed test shows you three numbers: download, upload, and ping. Download tells you whether you can stream video and browse smoothly. Upload tells you whether video calls will work without freezing. Ping tells you whether online games will feel responsive.
For most people, 25 Mbps download is enough for one person to stream video and browse. 50 Mbps handles multiple people streaming at once. 100 Mbps or higher is useful if you work from home, stream 4K video, or have a large household. Upload speed matters less for most people — 5 Mbps is enough for video calls and cloud backup, though 10 Mbps is better if you upload video regularly.
If your measured speed is consistently much lower than your plan promises — say, you pay for 100 Mbps but measure 40 Mbps or lower — contact your provider with your speed test results. They can check whether the problem is on their end or in your home setup. If the problem is in your home, they may suggest moving your router, upgrading your modem, or switching to ethernet.
Different speed test tools may show slightly different results
Speedtest.net, Fast.com, and your provider's own speed test tool will not always show the same number. The differences are usually small — within 10 percent — but they can vary because each tool tests to a different server and measures slightly differently.
Use the same tool each time you test so you can track changes over time. If you are troubleshooting a problem, run the test multiple times on the same tool at different times of day. A single test result is a snapshot; a pattern across multiple tests tells you whether something is actually wrong.
Frequently Asked Questions
Why is my speed test result lower than my plan speed?
Network congestion, distance from the test server, WiFi interference, and the limits of your equipment all reduce your measured speed below the plan maximum. This is normal. If your measured speed is consistently 30 percent or more below your plan speed, contact your provider with your test results.
Does ping matter if I do not play online games?
Ping matters for video calls and live video streaming too. Ping above 150 ms makes video calls feel delayed and awkward. For browsing and regular streaming, ping does not matter much — download speed is what counts.
Should I test on WiFi or ethernet?
Test on ethernet if you want to know your plan's true speed, since WiFi is always slower. Test on WiFi if you want to know what you actually experience in your home. Testing both tells you whether WiFi is the bottleneck.
What upload speed do I need for video calls?
Zoom, Google Meet, and Teams work on 2.5 Mbps upload for one person. If multiple people in your household are on video calls at once, you need 5 Mbps or higher. Check your measured upload speed during a call to see whether it is the problem if calls freeze or drop.
Can I improve my speed without changing my plan?
Move closer to your router, remove obstacles between you and it, or switch to ethernet. Restart your modem and router. If you have an old modem, ask your provider whether a newer one would help. These steps often improve measured speed by 10 to 30 percent without changing your plan.