Breaking Down the Units: Bits, Bytes, Mbps, and Gbps

When your internet provider advertises a plan, the speed is listed in megabits per second (Mbps) or gigabits per second (Gbps). These units measure how much data can travel through your connection in one second — think of it like the width of a pipe: a wider pipe moves more water at once.

A common point of confusion is the difference between bits and bytes. Files on your device are measured in bytes (MB, GB), but internet speeds are measured in bits. There are 8 bits in every byte, which means a 100 Mbps connection can theoretically download about 12.5 megabytes of data per second — not 100 megabytes. File sizes and speed units don't share the same scale, and that gap can make download times seem confusing at first glance.

For context on other networking terminology, see our plain-English home networking glossary.

Download vs. Upload: Two Different Lanes

Every internet plan comes with two speed figures: download and upload. They describe traffic moving in opposite directions.

  • Download speed governs how fast data arrives at your home — streaming video, loading web pages, receiving emails with attachments.
  • Upload speed governs how fast data leaves your home — video calls, cloud backups, posting videos, or sharing large files.

Most households consume far more data than they send, so providers historically prioritized download speeds. Cable internet plans, for example, commonly offer download speeds of 200–500 Mbps while upload speeds may be only 10–20 Mbps. This asymmetry rarely matters for casual browsing, but it becomes noticeable on Zoom calls or when backing up photos to the cloud.

Fiber internet connections tend to offer symmetrical speeds — equal download and upload — which is increasingly relevant as remote work and video conferencing have become routine. For a deeper look at how connection technology shapes speed, see our article on home internet connection types.

25 Mbps

FCC minimum broadband download speed standard

The U.S. Federal Communications Commission has used 25 Mbps download / 3 Mbps upload as its baseline definition of broadband, though this threshold has been under review as usage demands increase.

8x

Bits per byte — a key conversion factor

Because speeds are measured in bits and file sizes in bytes, a 100 Mbps connection transfers roughly 12.5 megabytes per second in real-world file transfers, not 100 megabytes.

~20 ms

Typical latency target for online gaming

Industry guidance generally cites latency below 20–40 milliseconds as ideal for real-time gaming and video calls, with anything above 100 ms likely to produce noticeable lag.

Latency: The Speed Number That Doesn't Show Up on Your Plan

Speed in Mbps only tells part of the story. Latency — commonly called ping — measures the round-trip time for a small data packet to travel between your device and a server, expressed in milliseconds (ms). It's entirely separate from bandwidth.

A connection can be fast but laggy. Imagine a wide highway where every vehicle has to stop at a checkpoint: lots of cars can travel, but each one takes longer to arrive. High latency creates that checkpoint effect — data requests take longer to get a response even if large amounts of data can move simultaneously.

Latency under 20–40 ms is generally considered excellent for real-time applications. Online gaming, live video calls, and remote desktop access are all sensitive to latency spikes. Satellite internet connections, despite sometimes offering acceptable Mbps figures, have historically struggled with high latency due to the physical distance signals must travel. Reading a Wi-Fi speed test explains how to measure your own ping and what the result means for your connection's health.

How Much Speed Do You Actually Need?

Internet providers often market the highest tier plans, but most households don't need gigabit speeds for everyday use. What matters is how many devices are active simultaneously and what those devices are doing.

A useful way to think about it: each simultaneous activity draws from a shared pool of bandwidth. One person streaming 4K video while another joins a video call and a third downloads a software update can collectively consume 50–75 Mbps. If your plan only offers 25 Mbps, everyone experiences slowdowns.

If your speeds seem lower than expected even on a high-tier plan, the issue often isn't the plan itself. Router placement, outdated equipment, and Wi-Fi interference can all drag performance down. Our article on common causes of slow home internet walks through the most frequent culprits.

Test Your Speed With a Wired Connection First

For the most accurate reading of your plan's performance, connect a laptop directly to your router using an Ethernet cable before running a speed test. Wi-Fi introduces variables — distance, interference, router age — that can make results look worse than your actual plan delivers. Once you have a wired baseline, you can evaluate whether Wi-Fi performance is the limiting factor.