Bits, Bytes, and the Advertising Trick Everyone Falls For
Every internet plan is sold in bits per second (Mbps, Gbps). Every file on your disk is measured in bytes (MB, GB). The gap between the two is a factor of exactly 8, and it is the single most misunderstood number in consumer technology. When an ISP advertises "1 Gig," they mean 1,000 Mbps = 1 Gbps of raw bit capacity. Divide by 8 and you get 125 MB/s — the fastest any single file can possibly download on that connection, before overhead. Most people expect "a gig" to feel like 1,000 MB/s and are baffled when a 10 GB game takes 80+ seconds. It's not throttling; it's the bits-to-bytes ratio they never told you in the commercial.
There's a historical reason bits won. Early telecommunications measured the rate of a serial signal — one bit after another down a wire — so "bits per second" was the natural unit. Storage, meanwhile, was built around the byte (8 bits) as the addressable unit of memory. The two worlds never reconciled, and now we live in the seam: networks speak bits, disks speak bytes, and the only thing connecting them is a ÷8 that appears on no billboard.
Common Connection Speeds, Decoded
| Plan (bit rate) | In Gbps | Realistic download (÷8, minus overhead) | Typical use |
|---|---|---|---|
| 50 Mbps | 0.05 Gbps | ~6 MB/s | Small household, HD streaming. |
| 100 Mbps | 0.1 Gbps | ~12 MB/s | Several 4K streams, video calls. |
| 300 Mbps | 0.3 Gbps | ~35 MB/s | Busy smart home. |
| 500 Mbps | 0.5 Gbps | ~58 MB/s | Heavy cloud backup, large downloads. |
| 1,000 Mbps ("1 Gig") | 1 Gbps | ~110–125 MB/s | Enthusiast / future-proof. |
| 2,000 Mbps ("2 Gig") | 2 Gbps | ~225–240 MB/s | Need multi-gig NIC + CAT6e wiring. |
| 10 Gbps (business) | 10 Gbps | ~1,000–1,150 MB/s | Datacenter, enterprise edge. |
Gbps = Mbps ÷ 1,000 Mbps = Gbps × 1,000
And remember: real MB/s ≈ Mbps ÷ 8
Worked Examples
940 Mbps fiber → 0.94 Gbps
"Gigabit" fiber is almost never a true 1,000 Mbps; the provisioning overhead reserves ~6% for network management, so you get ~940 Mbps (0.94 Gbps). Divide by 8 and a Steam download tops out around 110 MB/s. That's still excellent — a 100 GB game installs in ~15 minutes — but it is not the 1,000 MB/s the word "gigabit" implies. The 940 number is honest engineering; the "1 Gig" label is marketing rounding.
A 4K Netflix stream → ~25 Mbps (0.025 Gbps)
One Ultra-HD stream needs roughly 25 Mbps. On a 1 Gbps (1,000 Mbps) connection, that's just 2.5% of capacity — you could run ~35 simultaneous 4K streams before saturating the link. This is why "do I need gigabit for streaming?" is almost always no; 100–200 Mbps covers a whole family. The people who need 1 Gbps are downloading 100 GB game updates or pushing 4K video to YouTube, where upload (often capped at 20–50 Mbps on cable) is the real constraint, not download.
Wi-Fi 5 (802.11ac) → ~866 Mbps (0.866 Gbps) theoretical
A single-stream 802.11ac link is rated up to 866 Mbps, but real-world walls, interference, and distance cut that to 300–500 Mbps. Wi-Fi 6 (802.11ax) pushes single-stream to ~1.2 Gbps (1.2 Gbps) on paper, ~600–800 Mbps real. The lesson: even if you pay for 1 Gbps, your phone over Wi-Fi rarely sees it unless you're close to a good router on 5 GHz or 6 GHz. The bottleneck is the last meter, not the fiber. Converting your plan's Gbps to Mbps only tells you the ceiling, not what your device experiences.
Backbone transit → 100–400 Gbps per wavelength
Under the ocean, a single fiber "wave" carries 100–400 Gbps, and a cable bundles many waves — a transatlantic cable like MAREA carries 224 Tbps total (224,000 Gbps) across eight fiber pairs. Your 1 Gbps home connection is one ten-billionth of that capacity. The economics of the internet are pure aggregation: millions of 1 Gbps households share a 224 Tbps spine, and the magic of packet switching is that nobody notices — until a cable is cut and latency reroutes across a continent.
Why Network Speeds Stay Decimal (No 1,024 Here)
Unlike storage, where "MB" sometimes means 1,048,576 bytes (binary) and sometimes 1,000,000 (decimal) — the source of the "1 TB shows 931 GB" complaint — network rates are unambiguous. Telecommunications standards define Mbps and Gbps strictly in decimal SI: 1 Mbps = 1,000,000 bits; 1 Gbps = 1,000,000,000 bits. There is no 1,024 in bandwidth. So when you convert 1,000 Mbps to 1 Gbps, the factor is a clean thousand, every time. If you've been bitten by the binary/decimal storage confusion, relax here: networks don't play that game. (For the storage side of the story, see the data-storage guide and tools like MB to GB.)
Engineering Context
Mbps-to-Gbps is a bit-rate conversion — it describes throughput, not capacity. The matching capacity unit is the byte (MB, GB, TB), and the bridge between them is always ÷8. When sizing a network, engineers think in both: link rate in Gbps (how fast the pipe is) and transferred volume in GB (how much moved). A common mistake is budgeting "we need 10 Gbps" when the real requirement is "move 5 TB nightly," which at 1 Gbps takes ~12 hours but at 10 Gbps takes ~1.2 hours — a clean Mbps/Gbps ÷ 8 ÷ 3,600 calculation. Related: storage-size conversions MB to GB, KB to MB, GB to TB, and the full Data Storage Guide on the binary/decimal collision.
Related Unit Converters
Frequently Asked Questions
Is 5G faster than my home Wi-Fi in Gbps?
Usually not at the link level, but it can be in practice. A good 5G connection delivers 100–500 Mbps (0.1–0.5 Gbps) down in ideal conditions, occasionally spiking to 1–2 Gbps (1–2 Gbps) near a tower with mmWave. A modern Wi-Fi 6 home network easily does 600–940 Mbps (0.6–0.94 Gbps) to a close device. So Wi-Fi is typically faster for a stationary device; 5G wins for mobility and when your home broadband is slow. The Gbps number on a 5G plan often refers to a theoretical peak few users sustain — real median 5G speeds are closer to 150–200 Mbps (0.15–0.2 Gbps).
Why is my upload speed so much slower than download?
Asymmetric routing. Cable and legacy DSL networks were designed when consumers downloaded far more than they uploaded, so they allocate more downstream channels. A "1 Gig" cable plan might give 1,000 Mbps down but only 20–50 Mbps (0.02–0.05 Gbps) up — a 20–50× asymmetry. That upload cap is why livestreaming 4K to Twitch (needs ~15–25 Mbps up) is fine, but backing up a 2 TB drive to the cloud at 30 Mbps takes ~15 hours. Fiber-to-the-home is usually symmetric (1 Gbps down AND up); if upload matters to you, that's the feature to pay for, not raw download Gbps.
What's the difference between Mbps and MB/s written on speed tests?
They're the same quantity in different units, and the confusion is intentional-looking but technically honest. Speed-test apps (Ookla, fast.com) usually show Mbps (megabits per second) because that's the ISP's unit. File managers and download clients show MB/s (megabytes per second). To convert: MB/s × 8 = Mbps. So a test showing 750 Mbps means your download client should show ~94 MB/s. If the test says 750 Mbps but your Steam download shows 30 MB/s, the cause is server-side limits or Wi-Fi loss, not a broken test — the test measures the pipe, the client measures the end-to-end path, and the path has more bottlenecks than the pipe.
Do I need a special cable for multi-gigabit (2.5/5/10 Gbps)?
It depends on distance. Cat5e supports 2.5 Gbps and even 5 Gbps up to ~100 m in good conditions; 10 Gbps over Cat5e is unreliable beyond ~45 m. Cat6 handles 10 Gbps to 55 m; Cat6a to 100 m. So if your router and your PC are both multi-gig and connected by a short Cat5e run, you'll likely get 2.5–5 Gbps, but to guarantee 10 Gbps you want Cat6a. The catch most people miss: your network card, your router's LAN port, AND the cable must ALL support the speed — a 10 Gbps plan on a 1 Gbps NIC stays at 1 Gbps. Converting your plan's Gbps to a working link requires three matching endpoints, not one fast number.