Quick Answer
Internet speeds are sold in bits. File sizes are measured in bytes.
So to convert Mbps → GB/s, you divide by 8,000 (decimal) or 8,192 (binary), because you're converting both the unit (bits → bytes) and the scale (Mega → Giga) at the same time:
- 1 Mbps = 0.000125 GB/s (decimal, ÷8000)
- 1 Mbps = 0.000122 GB/s (binary, ÷8192)
This is the single most common speed-related confusion online: a "100 Mbps" internet plan does not mean you download at 100 GB per second — or even 100 MB per second. It means roughly 12.5 MB/s, because bits and bytes are different units, off by a factor of 8. For a deep dive into the difference between 1000 and 1024 conversions, check out our guide.
Why Mb ≠ MB (and Mbps ≠ MB/s)
| Symbol | Stands for | Used for |
|---|---|---|
| Mb / Mbps | Megabit / Megabits per second | Internet & network speeds (ISPs, routers, WiFi) |
| MB / MB/s | Megabyte / Megabytes per second | File sizes, storage, downloads |
| GB | Gigabyte | Storage, large file sizes |
| GB/s | Gigabytes per second | Actual data transfer rate of large files |
The lowercase b = bits. The uppercase B = bytes. It's a tiny visual difference that leads to a lot of confused customers wondering why their "500 Mbps" plan downloads a file at "only" 62.5 MB/s — that's actually correct math, not a slow connection. If you need to know more about the order of data sizes (KB, MB, GB, TB), we have a complete overview. For a deeper understanding of digital storage units, you can read more on the Wikipedia Data-rate units page.
Mbps to GB/s Conversion Table
| Mbps | MB/s | GB/s |
|---|---|---|
| 10 Mbps | 1.25 MB/s | 0.00125 GB/s |
| 25 Mbps | 3.125 MB/s | 0.003125 GB/s |
| 50 Mbps | 6.25 MB/s | 0.00625 GB/s |
| 100 Mbps | 12.5 MB/s | 0.0125 GB/s |
| 250 Mbps | 31.25 MB/s | 0.03125 GB/s |
| 500 Mbps | 62.5 MB/s | 0.0625 GB/s |
| 1,000 Mbps (1 Gbps) | 125 MB/s | 0.125 GB/s |
| 2,000 Mbps (2 Gbps) | 250 MB/s | 0.25 GB/s |
| 5,000 Mbps (5 Gbps) | 625 MB/s | 0.625 GB/s |
| 10,000 Mbps (10 Gbps) | 1,250 MB/s | 1.25 GB/s |
*(Decimal basis: 1 byte = 8 bits, 1 GB = 1,000 MB. Real-world speeds are usually 10–20% lower than advertised due to network overhead. See our Mbps to Gbps conversion for details.)*
How to Convert Mbps to GB/s (Formula)
or equivalently:
Example: You have a 200 Mbps connection. How many GB/s is that?
That's 25 MB/s — meaning a 1 GB file would take about 40 seconds under ideal conditions. To quickly convert between megabits and megabytes, use our Mbps to MB/s converter.
To go the other way (GB/s to Mbps), multiply by 8,000:
How Long Will My Download Actually Take?
This is usually the real question behind "Mbps to GB/s." Here's a practical table using common internet speeds and file sizes. For custom sizes, use our download time calculator.
1 GB File (TV Episode)
50 GB File (Modern Video Game)
*Real-world speeds are typically 70–90% of advertised speed due to network overhead, WiFi signal loss, and server-side limits — so treat these as best-case estimates.
Frequently Asked Questions
Is 100 Mbps fast enough to download a 10 GB game quickly?
At a true 100 Mbps (12.5 MB/s), a 10 GB game takes roughly 13–14 minutes under ideal conditions. Real-world speeds are often lower, so expect closer to 15–20 minutes in practice.
Why does my download speed show MB/s but my plan says Mbps?
Internet service providers advertise speed in megabits per second (Mbps), but download managers and browsers typically show progress in megabytes per second (MB/s). Since 1 byte = 8 bits, your actual download speed in MB/s will be roughly 1/8th of your plan's Mbps number.
What's the difference between Gbps and GB/s?
Gbps (gigabits per second) measures network/connection speed. GB/s (gigabytes per second) measures file transfer rate. 1 Gbps ≈ 0.125 GB/s (125 MB/s) — the same bit-to-byte factor of 8 applies at every scale.
How do I convert GB/s back to Mbps?
Multiply the GB/s value by 8,000 (or by 8,192 if using binary/1,024-based units). For example, 0.5 GB/s × 8,000 = 4,000 Mbps.
Why is my actual download speed slower than my advertised Mbps?
Advertised speeds represent the theoretical maximum. Actual throughput is affected by network congestion, WiFi signal strength, the server you're downloading from, protocol overhead, and how many devices share your connection. A 70–90% real-world efficiency rate is typical.
Do I need Mb or GB when checking cloud storage or upload limits?
Storage limits (cloud storage, file size caps, hard drive space) are almost always in GB or MB (bytes). Connection speed limits (your internet plan, WiFi router spec, ISP throttling) are almost always in Mbps or Gbps (bits). Check which one you're being quoted before comparing numbers.
Related Tools
- MB ↔ GB Data Size Calculator — for converting exact file and storage sizes
- Download Time Calculator
- Mbps to Gbps Converter
- Mbps to MB/s Converter
- MB to GB Converter
*This page uses the decimal standard (1 byte = 8 bits, 1 GB = 1,000 MB) to match how ISPs and network hardware report speeds. Toggle the converter above for binary (1,024-based) results if needed for OS-level comparisons.