Convert megabits per second to megabytes per second instantly — and back. Covers all speed units: Kbps, Mbps, Gbps, Tbps to KB/s, MB/s, GB/s, TB/s. Find out your real download speed and see how your connection compares across all device types.
✓Verified: IEC 80000-13 data rate standards & ITU-T unit definitions — April 2026
🔄 Speed Unit Converter
Enter your internet or network speed in bits per secondEnter a valid speed value greater than 0.
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divide by 8 (1 byte = 8 bits)
MB/s Result
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⚠️ Disclaimer: Conversion uses SI decimal standards (1 Mbps = 1,000,000 bps; 1 MB/s = 1,000,000 bytes/s). Real download speeds are 80–95% of theoretical due to TCP/IP protocol overhead.
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Enter your file transfer or download speed in bytes per secondEnter a valid speed value greater than 0.
➡
multiply by 8 (1 byte = 8 bits)
Mbps Result
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Enter the speed your ISP advertises (from your plan)Enter a valid speed value greater than 0.
Expected Download Speed
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Sources & Methodology
✓Conversion uses SI decimal standards per IEC 80000-13 and ITU-T definitions. 1 byte = 8 bits exactly. 1 Mbps = 1,000,000 bits per second. 1 MB/s = 1,000,000 bytes per second. Real-world efficiency factors based on published TCP/IP and IEEE 802.11 protocol documentation.
International Telecommunication Union standards defining data rate units including bits per second and bytes per second as used in network speed measurement and communication system design.
Defines the SI decimal and binary (IEC) standards for data measurement including megabit, megabyte, mebibyte, and their per-second rates. The source of the exact 1 byte = 8 bits conversion used throughout this calculator.
IEEE Wi-Fi standard defining real-world throughput characteristics and efficiency factors for wireless connections used in this calculator's connection type efficiency estimates.
Methodology: Mbps to MB/s: MB/s = Mbps / 8 (exact, SI decimal)MB/s to Mbps: Mbps = MB/s x 8 (exact, SI decimal)Real download speed = Theoretical max x connection efficiency factor
Unit convention: SI decimal throughout (1 MB = 1,000,000 bytes, matching ISP advertising and network equipment standards). Binary (IEC) convention: 1 MiB/s = 8.388608 Mbps. Efficiency factors: Wired ethernet 85 to 95% (TCP/IP overhead), Wi-Fi 70 to 85% (air interface + contention), mobile 50 to 70% (variable signal, cell loading). Verified against IEC 80000-13:2008.
Last reviewed: April 2026
Mbps vs MB/s: Complete Guide to Internet Speed Units 2026
The single most common source of confusion in home networking is the difference between Mbps and MB/s. If you have ever wondered why your 100 Mbps internet plan only shows 12 MB/s in your download progress bar, this guide explains everything. Understanding the bit-byte relationship is fundamental to reading speed test results, calculating download times, choosing the right plan, and understanding why ISPs advertise the way they do.
The Core Formula: Why You Divide by 8
The conversion between Mbps and MB/s comes directly from the definition of a byte. One byte equals exactly 8 bits — this is a fundamental standard in digital computing defined by IEC 80000-13. Since 1 megabit per second means one million bits per second, and one byte is eight bits, dividing by 8 converts from bits per second to bytes per second.
MB/s = Mbps ÷ 8 (divide by 8 to go from bits to bytes)Mbps = MB/s × 8 (multiply by 8 to go from bytes to bits)
This table covers all common broadband and network speeds. Use it as a quick reference to know what download speed to expect from any advertised connection.
Connection Speed
Theoretical MB/s
Real-world MB/s
1 GB Download Time
10 Mbps
1.25 MB/s
1.0–1.2 MB/s
~14 min
25 Mbps
3.125 MB/s
2.5–3.0 MB/s
~5.5 min
50 Mbps
6.25 MB/s
5.0–6.0 MB/s
~2.8 min
100 Mbps
12.5 MB/s
10–12 MB/s
~85 sec
200 Mbps
25 MB/s
20–24 MB/s
~43 sec
500 Mbps
62.5 MB/s
55–60 MB/s
~17 sec
1 Gbps (1,000 Mbps)
125 MB/s
110–118 MB/s
~8.5 sec
2.5 Gbps
312.5 MB/s
280–300 MB/s
~3.4 sec
10 Gbps
1,250 MB/s
1,100–1,200 MB/s
~0.9 sec
Why ISPs Advertise in Mbps (Not MB/s)
There are two reasons ISPs use Mbps in their advertising. The first is technical: network equipment, protocols, and telecommunications infrastructure are all fundamentally bit-based. Router interfaces, switching fabrics, and optical fiber are rated in bits per second. The second reason is marketing: 100 Mbps sounds far more impressive than 12.5 MB/s, even though they represent exactly the same speed. The larger number sells more plans. Both representations are technically accurate — neither is misleading on its own, but the inconsistency with how file sizes are measured creates widespread confusion.
Real-World Speed vs Theoretical Speed: The Gap Explained
Even with the best connection, your actual download speed is always slightly below the theoretical maximum. On a 100 Mbps connection the theory says 12.5 MB/s but you will see 10 to 12 MB/s. The gap comes from three sources. TCP/IP protocol headers account for 3 to 5 percent of all traffic. Network congestion during peak hours reduces available bandwidth. And most residential connections are shared infrastructure with neighbors. Ethernet delivers 92 to 95 percent efficiency. Wi-Fi on 5 GHz delivers 80 to 85 percent. Wi-Fi on 2.4 GHz delivers 65 to 75 percent due to interference and channel contention. 4G LTE delivers 55 to 70 percent depending on signal strength and cell loading.
SI Decimal vs Binary (IEC): Which One to Use
Two competing standards define the megabyte. The SI decimal standard (used by ISPs, hard drive manufacturers, and this calculator) defines 1 MB as exactly 1,000,000 bytes. The binary IEC standard (used by Windows OS and RAM) defines 1 MiB (mebibyte) as 1,048,576 bytes (2 to the power of 20). The difference is 4.86 percent. For internet speed conversion, always use SI decimal (divide Mbps by exactly 8). The binary standard applies to RAM and file size displays in Windows Explorer, not to network speeds. Using the wrong standard introduces a small error but does not fundamentally change results at typical consumer speeds.
Speed Comparison: Devices and Technologies 2026
Technology
Advertised Speed
MB/s Equivalent
Real-world MB/s
USB 2.0
480 Mbps
60 MB/s
30–40 MB/s
USB 3.0 (Gen 1)
5 Gbps
625 MB/s
300–400 MB/s
USB 3.2 Gen 2
10 Gbps
1,250 MB/s
700–1,000 MB/s
Thunderbolt 4
40 Gbps
5,000 MB/s
2,500–3,500 MB/s
Wi-Fi 5 (5 GHz)
867 Mbps
108 MB/s
75–90 MB/s
Wi-Fi 6 (5 GHz)
2,400 Mbps
300 MB/s
200–250 MB/s
Wi-Fi 7 (6 GHz)
5,760 Mbps
720 MB/s
400–600 MB/s
4G LTE (avg)
150 Mbps
18.75 MB/s
8–15 MB/s
5G mmWave
4,000 Mbps
500 MB/s
100–300 MB/s
NVMe SSD (PCIe 4)
32,000 Mbps
4,000 MB/s
3,000–7,000 MB/s
💡 Key insight: Your NVMe SSD reads at 4,000+ MB/s but your gigabit internet delivers 125 MB/s — storage is already 30x faster than your internet connection. For most users, internet speed (not storage) is the bottleneck for downloads. For local file transfers, it is the opposite.
Frequently Asked Questions
Divide megabits per second (Mbps) by 8 to get megabytes per second (MB/s). Formula: MB/s = Mbps / 8. Example: 100 Mbps / 8 = 12.5 MB/s. Example: 50 Mbps / 8 = 6.25 MB/s. Example: 1000 Mbps / 8 = 125 MB/s. The division by 8 comes from the definition of a byte: 1 byte = 8 bits, defined by IEC 80000-13.
Mbps (lowercase b) = megabits per second, used to measure network and internet connection speeds. MB/s (uppercase B) = megabytes per second, used to measure file transfer and download speeds. Since 1 byte = 8 bits, MB/s is always 8 times smaller numerically than Mbps. The same speed expressed as 100 Mbps is exactly 12.5 MB/s.
This is correct and expected. 100 Mbps = 12.5 MB/s maximum. Seeing 11 to 12 MB/s means you are getting 88 to 96 percent of theoretical maximum, which is entirely normal. The remaining gap is TCP/IP protocol overhead (3 to 5 percent of all traffic goes to headers and acknowledgments). Your ISP is delivering your full advertised speed.
Two reasons: Technical accuracy (network protocols and hardware operate in bits) and marketing (100 Mbps sounds more impressive than 12.5 MB/s). Both representations are equally correct, but the inconsistency with file size measurement (bytes) creates confusion. Memorize: divide by 8 to convert ISP speeds to download progress speeds.
1 Gbps = 1,000 Mbps / 8 = 125 MB/s theoretical maximum. Real-world on wired ethernet: 110 to 118 MB/s. A gigabit connection can transfer 1 GB in approximately 8 to 9 seconds, download a 4K movie (15 GB) in about 2 minutes, and a 50 GB game in about 7 minutes.
Multiply megabytes per second (MB/s) by 8 to get megabits per second (Mbps). Formula: Mbps = MB/s x 8. Example: 10 MB/s x 8 = 80 Mbps. Example: 50 MB/s x 8 = 400 Mbps. This is useful when you know your NAS or USB drive speed in MB/s and want to know what network connection speed is needed to keep up.
Kbps (kilobits per second) divided by 8 = KB/s (kilobytes per second). Example: 256 Kbps / 8 = 32 KB/s. Example: 1,000 Kbps = 1 Mbps = 125 KB/s. Kbps is used for older or low-bandwidth connections like dial-up (56 Kbps = 7 KB/s), voice calls (64 Kbps), and IoT sensor data links.
Gbps (gigabits per second) divided by 8 = GB/s (gigabytes per second). 1 Gbps = 0.125 GB/s = 125 MB/s. 10 Gbps = 1.25 GB/s. 100 Gbps = 12.5 GB/s. Gbps is used for enterprise networking (10/40/100 Gbps switches), data center interconnects, and high-speed storage interfaces.
SI decimal (used by ISPs and network equipment): 1 MB = 1,000,000 bytes, so 1 MB/s = 8 Mbps exactly. Binary IEC (used by Windows and RAM): 1 MiB = 1,048,576 bytes, so 1 MiB/s = 8.388608 Mbps. For internet speed conversion, use SI decimal (divide by exactly 8). Windows showing file sizes in MiB while calling them MB is the source of apparent discrepancies in storage capacity displays.
500 Mbps = 62.5 MB/s theoretical maximum. Real-world download speed: 55 to 60 MB/s. At this speed you can download a 1 GB file in about 17 seconds, a 4K movie (15 GB) in about 4 minutes, and a 50 GB game in about 14 minutes. This is a common mid-tier fiber broadband speed.
25 Mbps = 3.125 MB/s theoretical. Real-world: 2.5 to 3.0 MB/s. This is enough for streaming 4K video (Netflix requires 15 to 25 Mbps) and 2 to 3 HD streams simultaneously. However, downloading large files like games or system updates is slow. A 50 GB game takes approximately 4.5 hours at 25 Mbps.
Wi-Fi does not change the Mbps to MB/s conversion formula (always divide by 8). However, Wi-Fi reduces the actual throughput you achieve vs your plan speed. Wired ethernet achieves 90 to 95 percent of your plan speed. Wi-Fi on 5 GHz achieves 75 to 85 percent. Wi-Fi on 2.4 GHz achieves 60 to 75 percent. So a 100 Mbps plan on 2.4 GHz Wi-Fi might deliver 8 to 9 MB/s instead of the theoretical 12.5 MB/s.
Run a speed test at Fast.com or Speedtest.net. These report in Mbps. Divide the result by 8 to get MB/s. Alternatively, download a large file and watch your browser or download manager, which shows speed in MB/s. For best accuracy: use wired ethernet, close all other apps and downloads, run the test at multiple times to check for congestion patterns, and compare results across days.