Bits and Bytes Converter
Convert any data size or transfer rate between bits, bytes, and all prefixed units — KB vs KiB, MB vs MiB, Mbps vs MB/s — in one table.
Bits, Bytes, and Data Units
Digital data is measured in bits and bytes. A bit is the fundamental unit — a single binary digit (0 or 1). A byte is 8 bits and is the standard unit for file sizes and storage.
Data units scale with prefixes. There are two competing prefix systems:
SI (decimal, powers of 1,000) — used by hard drive manufacturers, network equipment, and most consumer products:
- Kilobyte (KB) = 1,000 bytes
- Megabyte (MB) = 1,000,000 bytes
- Gigabyte (GB) = 1,000,000,000 bytes
- Terabyte (TB) = 1,000,000,000,000 bytes
IEC (binary, powers of 1,024) — used by operating systems, RAM, and programming:
- Kibibyte (KiB) = 1,024 bytes
- Mebibyte (MiB) = 1,048,576 bytes
- Gibibyte (GiB) = 1,073,741,824 bytes
- Tebibyte (TiB) = 1,099,511,627,776 bytes
The two systems diverge significantly at scale: 1 TB = 931 GiB. This explains why a “1 TB” hard drive appears as ~931 GB in your operating system.
Data rates (network speeds, disk I/O) are measured in bits per second: Kbps, Mbps, Gbps. To convert to bytes per second, divide by 8: 100 Mbps = 12.5 MB/s.
Formula
Conversion via bits (the universal intermediate): bits = value × bits_per_unit result = bits ÷ bits_per_unit_of_target
Key equivalences:
- 1 byte = 8 bits
- 1 nibble = 4 bits (= ½ byte)
- 1 KB = 1,000 bytes (SI) or 1 KiB = 1,024 bytes (IEC)
- Mbps ÷ 8 = MB/s (megabits per second to megabytes per second)
How to Use
- Enter a value — type any number representing a data quantity (file size, network speed, storage capacity).
- Select the source unit — choose from the full list of storage units (bit through PB) and rate units (Kbps through GB/s).
- Click Convert — a complete table shows all storage and rate equivalents simultaneously.
- Compare SI vs IEC — the table shows both KB and KiB, both MB and MiB, etc., so you can see the difference at a glance.
- Use the steps — the working panel shows the intermediate bits calculation and the conversion factor.
Example Calculations
Example 1 — 1 GB: How Many MB, MiB, Bits?
Convert 1 GB (SI gigabyte)
1
1 GB = 1,000 MB = 1,000,000 KB = 1,000,000,000 bytes (SI)
2
In IEC binary: 1 GB = 1,000,000,000 / 1,073,741,824 = 0.9313 GiB = 953.674 MiB
3
In bits: 1,000,000,000 bytes × 8 = 8,000,000,000 bits = 8 Gbits
1 GB = 1,000 MB = 953.7 MiB = 8 Gbits. The OS reports 0.931 GiB, not 1 GiB.
Try this example →Example 2 — 100 Mbps Internet Connection
Convert 100 Mbps to MB/s, KB/s, and transfer time for 1 GB
1
100 Mbps ÷ 8 = 12.5 MB/s
2
12.5 MB/s = 12,500 KB/s = 12.5 × 10³ KB/s
3
Time for 1 GB: 1,000 MB ÷ 12.5 MB/s = 80 seconds
100 Mbps = 12.5 MB/s. A 1 GB file downloads in 80 seconds (theoretical; real-world ~56–90s).
Try this example →Example 3 — 500 MB: Bits and All Prefixed Forms
Convert 500 MB to all units
1
500 MB = 500,000 KB = 0.5 GB (SI)
2
In IEC: 500,000,000 bytes ÷ 1,048,576 = 476.84 MiB
3
In bits: 500,000,000 × 8 = 4,000,000,000 bits = 4 Gbits
500 MB = 476.8 MiB = 4 billion bits = ~3.9 Gib
Try this example →❓ Frequently Asked Questions
What is the difference between a bit and a byte?
A bit (b) is the smallest unit of digital data — a single binary digit (0 or 1). A byte (B) is 8 bits. Network speeds are measured in bits per second (Mbps); file sizes are in bytes (MB). To avoid confusion: bit uses lowercase b, byte uses uppercase B. So “100 Mbps” is megabits per second; “12.5 MBps” is megabytes per second (which is 8× smaller).
What is the difference between KB and KiB?
KB (kilobyte) in SI = 1,000 bytes (10³). KiB (kibibyte) in IEC = 1,024 bytes (2¹⁰). The ~2.4% difference at kilo-scale grows to ~10% at tera-scale: 1 TB = 10¹² bytes; 1 TiB = 2⁴⁰ ≈ 1.0995 × 10¹² bytes. Drive makers use SI (so 1 TB drive = 10¹² bytes), while OSes historically used binary units — hence a “1 TB” drive shows as 931 GiB in Windows.
How do you convert Mbps to MB/s?
Divide by 8: MB/s = Mbps ÷ 8. This is because there are 8 bits per byte. Examples: 100 Mbps = 12.5 MB/s; 500 Mbps = 62.5 MB/s; 1 Gbps = 125 MB/s; 10 Gbps = 1,250 MB/s (1.25 GB/s). When your ISP says “100 Mbps” and Chrome shows “12.5 MB/s” — those are the same speed expressed in different units.
Why does my hard drive show less capacity than advertised?
Drive manufacturers use SI decimal (1 TB = 10¹² bytes). Windows reports in binary units historically labelled “GB”: 10¹² bytes ÷ 2³&sup0; bytes/GiB = 931.3 GiB, displayed as “931 GB”. macOS switched to SI in 2009 and shows the drive correctly as 1 TB. No storage is “missing” — it’s a naming difference. On a 1 TB drive you get exactly 10¹² bytes.
What is a nibble?
A nibble is 4 bits — half a byte. It’s significant because one nibble represents exactly one hexadecimal digit (0–F, i.e., 0–15 in decimal). A byte (8 bits) = two nibbles = two hex digits. The term “nibble” is a playful play on “byte” (as in “taking a smaller bite”). Nibbles are used in BCD (Binary Coded Decimal) and in networking protocol field descriptions.
What are IEC binary prefixes?
IEC 80000-13 (2008) defined binary prefixes: kibi (Ki, 2¹⁰=1,024), mebi (Mi, 2²⁰), gibi (Gi, 2³&sup0;), tebi (Ti, 2⁴⁰), pebi (Pi, 2⁵⁰), exbi (Ei, 2⁶⁰). These are exact powers of 2. The SI prefixes (k, M, G, T) remain exact powers of 1,000. Using IEC notation (KiB, MiB, GiB) unambiguously means binary — essential for precise technical specifications.
How much data does 1 TB hold?
1 TB (SI) = 1,000,000,000,000 bytes. In practical terms: ~200,000 songs (MP3 at 5 MB each), ~250,000 photos (4 MB each), ~500 HD movies (2 GB each), ~1,000 hours of HD video. As a 1 TiB = 2⁴⁰ ≈ 1.0995 × 10¹² bytes — about 10% more than 1 TB. Modern NVMe SSDs offer 1–8 TB; enterprise SANs measure in petabytes (1,000 TB).
What is the fastest data transfer rate available?
As of 2026: Thunderbolt 5: 120 Gbps theoretical; PCIe 5.0 ×16: ~256 Gbps; InfiniBand HDR: 200 Gbps per port; 800GbE Ethernet: 800 Gbps per port (data centre). Research links exceed 1 Pbps (petabits per second) in lab conditions over single optical fibers using wavelength division multiplexing. Standard home NVMe SSDs: 3–7 GB/s sequential read (24–56 Gbps).
How much internet bandwidth does 4K streaming require?
Netflix recommends 25 Mbps for 4K Ultra HD; YouTube 4K requires ~20 Mbps; Disney+ 4K requires 25 Mbps; Apple TV 4K requires 25 Mbps. For multiple simultaneous streams, multiply accordingly. In bytes per hour: 25 Mbps × 3,600 s = 90,000 Mb = 11,250 MB ≈ 11.25 GB/hour. A 4K movie of 2 hours ≈ 22.5 GB of data streamed (at consistent 25 Mbps).
How long does it take to transfer 1 TB over different connections?
1 TB = 8 Tbits = 8,000 Gbits. Transfer time = 8,000 Gbits ÷ speed: 100 Mbps (0.1 Gbps): ~22.2 hours; 1 Gbps: ~133 minutes; 10 Gbps: ~13.3 minutes; 100 Gbps: ~80 seconds; 1 Tbps: ~8 seconds. These are theoretical maximums at 100% utilization. Add 20–30% for real-world overhead. Use the Bandwidth Calculator for specific transfer time estimates.