Convert between bytes, KB, MB, GB, TB, PB and binary units (KiB, MiB, GiB, TiB) — instantly.
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This free data storage converter lets you instantly switch between bits, bytes, kilobytes (KB), megabytes (MB), gigabytes (GB), terabytes (TB), petabytes (PB), exabytes (EB), and the IEC binary units KiB, MiB, GiB, and TiB. Whether you are calculating how many photos fit on your phone, comparing cloud storage plans, figuring out why your "1 TB" hard drive shows as 931 GB in Windows, or working on a development project that requires precise byte-level arithmetic, this tool gives you the exact answer in one step.
Digital storage is one of those topics where two parallel systems of measurement coexist in everyday use — and the gap between them causes genuine confusion for millions of people every year. Understanding which system applies to which context is a practical skill for anyone who buys devices, manages data, works in IT, or just wants to know how much storage they actually have. This guide covers every unit, every formula, and every real-world scenario where these conversions matter.
Every unit of digital storage is built on the same foundation: the bit, the smallest unit of digital information. A bit has exactly two possible states — 0 or 1 — corresponding to the off/on states of a transistor in a chip. Everything stored on every computer, phone, server, and cloud platform in the world is ultimately a sequence of bits. All larger units are simply powers of two (in binary) or powers of ten (in decimal) multiples of this foundation.
The single most confusing topic in digital storage is the coexistence of two measurement systems: binary (base-2, powers of 1,024) used by operating systems, and decimal (base-10, powers of 1,000) used by storage manufacturers and the SI unit standard. Both are internally consistent and both are used in legitimate, official contexts — but they produce different numbers for the same physical storage, which is where the confusion enters.
Here is the practical consequence: a hard drive or SSD marketed as "1 TB" by its manufacturer uses the decimal definition — it contains exactly 1,000,000,000,000 bytes. When you plug that drive into a Windows computer, Windows divides by 1,099,511,627,776 (the binary terabyte) and displays the result as approximately 931 GB. The drive is not short-changing you. Not a single byte is missing. It is purely a labeling difference — but one that surprises almost everyone encountering it for the first time.
The IEC (International Electrotechnical Commission) attempted to resolve this in 1998 by introducing the kibibyte (KiB), mebibyte (MiB), gibibyte (GiB) naming convention, where the "bi" signals binary. Under this system, 1 GiB is unambiguously 1,073,741,824 bytes and 1 GB is unambiguously 1,000,000,000 bytes. Adoption has been slow: Linux uses GiB correctly, macOS adopted it from Ventura onwards, but Windows continues to display GiB values labeled as GB.
All binary conversions use a factor of 1,024 between adjacent units. All decimal conversions use a factor of 1,000. The table below shows both, plus the exact byte counts for each unit.
| Unit | Abbr. | Exact Bytes (Binary) | Exact Bytes (Decimal) | Common Use |
|---|---|---|---|---|
| Byte | B | 1 | 1 | Single character, smallest addressable memory |
| Kilobyte | KB / KiB | 1,024 | 1,000 | Text files, web cookies, config files |
| Megabyte | MB / MiB | 1,048,576 | 1,000,000 | Photos, music, documents, emails with attachments |
| Gigabyte | GB / GiB | 1,073,741,824 | 1,000,000,000 | Films, games, phone storage, RAM, data plans |
| Terabyte | TB / TiB | 1,099,511,627,776 | 1,000,000,000,000 | Hard drives, SSDs, NAS devices, backups |
| Petabyte | PB | 1,125,899,906,842,624 | 1,000,000,000,000,000 | Enterprise storage, cloud data centers |
| Exabyte | EB | 1,152,921,504,606,846,976 | 1,000,000,000,000,000,000 | Global internet traffic, national archives |
| Convert From | Convert To | Formula | Example |
|---|---|---|---|
| Bytes | KB | KB = Bytes ÷ 1,024 | 2,048 B = 2 KB |
| KB | MB | MB = KB ÷ 1,024 | 5,120 KB = 5 MB |
| MB | GB | GB = MB ÷ 1,024 | 2,048 MB = 2 GB |
| GB | TB | TB = GB ÷ 1,024 | 4,096 GB = 4 TB |
| TB | PB | PB = TB ÷ 1,024 | 1,024 TB = 1 PB |
| MB | Bytes | Bytes = MB × 1,048,576 | 5 MB = 5,242,880 B |
| GB | MB | MB = GB × 1,024 | 3 GB = 3,072 MB |
| GB | Bytes | Bytes = GB × 1,073,741,824 | 2 GB = 2,147,483,648 B |
| TB | GB | GB = TB × 1,024 | 2 TB = 2,048 GB |
| Bits | Bytes | Bytes = Bits ÷ 8 | 800 bits = 100 B |
Understanding unit sizes in abstract is one thing; knowing how they map to actual files you encounter every day makes them instantly meaningful. The figures below reflect typical real-world sizes — they will vary with compression settings, resolution, duration, and software version.
Storage technology has advanced so rapidly that devices considered enormous a decade ago now fit in a pocket. Here is how real-world device capacities map across the unit scale — using decimal values as sold, which is how manufacturers label them.
| Device Type | Typical Capacity Range | Binary Display (OS) | Real-World Use Case |
|---|---|---|---|
| USB flash drive (budget) | 8 – 64 GB | 7.4 – 59.6 GiB | Document portability, OS installers |
| Smartphone internal storage | 64 – 1,000 GB | 59.6 – 931 GiB | Apps, photos, video, music |
| Laptop SSD (mainstream) | 256 GB – 1 TB | 238 – 931 GiB | OS, apps, documents, photos |
| Desktop SSD | 500 GB – 4 TB | 466 GiB – 3.6 TiB | OS, creative work, game library |
| Consumer HDD (desktop) | 1 – 20 TB | 931 GiB – 18.2 TiB | Media storage, backups, NAS |
| microSD card | 32 GB – 1 TB | 29.8 – 931 GiB | Cameras, drones, portable devices |
| NAS (home, 2-bay) | 4 – 32 TB | 3.6 – 29.1 TiB | Home media server, local backup |
| Enterprise NVMe SSD | 800 GB – 15 TB | 745 GiB – 13.6 TiB | Database servers, high-frequency trading |
| Tape cartridge (LTO-9) | 18 TB (native), 45 TB (compressed) | 16.4 TiB native | Cold archival, long-term backup |
| Cloud storage (consumer) | 5 GB – 30 TB | Varies | Photo backup, document sync, disaster recovery |
One source of persistent confusion is the fact that network speeds are measured in bits per second while file sizes are measured in bytes. This is not an oversight — it reflects different engineering traditions that have persisted since the earliest days of digital networking.
Telecom engineers originally measured circuit capacity in bits per second because individual bits are transmitted serially (one at a time) over a wire or radio channel. Storage engineers measured capacity in bytes because memory chips store and address data in 8-bit groups. Both conventions became entrenched and remain in use today.
The practical consequence: to find your real download speed in megabytes per second (MB/s), divide your Mbps connection speed by 8. A "100 Mbps" broadband connection delivers a maximum of 12.5 MB/s. A "1 Gbps" fiber connection delivers up to 125 MB/s. Actual throughput is always somewhat lower due to protocol overhead, network congestion, and the speed of the server you are downloading from.
| Connection Speed | Max Download (MB/s) | 1 GB file download time | 1 TB file download time |
|---|---|---|---|
| 10 Mbps (basic broadband) | 1.25 MB/s | ~13.7 min | ~9.5 days |
| 50 Mbps | 6.25 MB/s | ~2.7 min | ~1.9 days |
| 100 Mbps (common fibre) | 12.5 MB/s | ~1.4 min | ~22.9 hours |
| 500 Mbps | 62.5 MB/s | ~16 sec | ~4.6 hours |
| 1 Gbps (gigabit fibre) | 125 MB/s | ~8 sec | ~2.3 hours |
| 10 Gbps (enterprise) | 1,250 MB/s | <1 sec | ~14 min |
Cloud storage has made petabytes of capacity accessible to ordinary consumers, but choosing the right plan requires knowing how much space your actual files consume. Here is a practical guide based on common usage scenarios.
Both definitions exist simultaneously, and both are officially recognized — which is the source of the confusion. In the decimal (SI) system used by storage device manufacturers, internet service providers, and telecom companies, 1 MB = 1,000 KB = 1,000,000 bytes exactly. In the binary system used by operating systems (Windows, Linux, macOS), 1 MB = 1,024 KB = 1,048,576 bytes. The IEC introduced separate names in 1998 to resolve this: 1 mebibyte (MiB) = 1,024 KiB (binary), while 1 MB officially means 1,000 KB (decimal). In everyday consumer use, "MB" almost always means the binary version when referring to files on a computer, and the decimal version when used by ISPs for data plan limits. This converter uses binary (1,024) by default.
This is the most commonly asked storage question, and the answer is entirely about labeling systems — not missing space. Hard drive manufacturers use the decimal definition: 1 TB = 1,000,000,000,000 bytes exactly. Windows displays storage in binary units, dividing by 1,099,511,627,776 (the binary terabyte). So: 1,000,000,000,000 ÷ 1,099,511,627,776 = 0.9095 TB, which Windows displays as approximately 931 GB. Every single byte is present and accounted for. macOS Ventura and later correctly labels the same drive as 1 TB because Apple switched to decimal units for storage display. Linux tools like df use binary by default and show ~931 GiB.
MB (megabyte) and MiB (mebibyte) differ by approximately 4.86%. 1 MiB = 1,048,576 bytes (1,024²); 1 MB = 1,000,000 bytes (1,000²) under the SI standard. The "i" in MiB signals the IEC binary prefix. In practice: when a Linux system shows a file as "500 MiB," it means exactly 524,288,000 bytes. When a network provider says your plan includes "500 MB" per day, they almost certainly mean 500,000,000 bytes (decimal). When Windows Explorer shows a file as "500 MB," it technically means 524,288,000 bytes (what should be called 500 MiB). The mismatch is real, institutionalized, and unlikely to fully resolve — so knowing both definitions is the practical solution.
Streaming data consumption depends heavily on video quality, codec efficiency, and the platform's bitrate settings. Standard definition (SD, 480p) typically uses 0.5–1 GB per hour. High definition (HD, 1080p) uses 3–5 GB per hour on most platforms. 4K Ultra HD ranges from 7 GB per hour (Netflix, which uses efficient compression) to 15–20 GB per hour (YouTube 4K, which uses higher bitrates). HDR content adds roughly 10–20% additional data compared to SDR at the same resolution. Music streaming is far lighter: standard quality (96 kbps) uses about 43 MB per hour; high quality (320 kbps) uses about 144 MB per hour; lossless (FLAC via services like Tidal or Apple Music Lossless) uses 300–1,200 MB per hour depending on resolution.
The answer depends entirely on your camera, resolution, and file format. A typical smartphone JPEG at 12 megapixels averages 3–5 MB, so 1 GB holds roughly 200–340 photos. iPhone HEIC photos are more compressed and typically 1.5–3 MB each, giving you 330–680 photos per GB. DSLR RAW files at 24 megapixels average 25–35 MB each, meaning 1 GB holds only 28–40 RAW images. Medium format RAW files (50+ megapixels) can reach 80–120 MB each, leaving room for just 8–12 images per GB. For practical planning: a 256 GB smartphone at default iPhone JPEG quality can hold roughly 51,000–85,000 photos.
1 petabyte (PB) = 1,024 terabytes (binary). To make the scale tangible: 1 PB of storage could hold approximately 200 million MP3 songs (about 38,000 years of continuous music), 223,000 standard DVD-quality movies, 500 billion pages of standard printed text, or 13.3 years of continuous HD video. Google processes multiple petabytes of search queries every day. The entire digitized catalog of the US Library of Congress is approximately 10–15 petabytes. The Large Hadron Collider at CERN generates about 15 petabytes of collision data annually. Consumer NAS devices now reach 100+ terabytes — 0.1 petabyte — so the petabyte era is arriving at the consumer level within this decade.
Using binary (for operating system file sizes): multiply GB by 1,024. So 5 GB = 5 × 1,024 = 5,120 MB. Using decimal (for storage devices and data plans): multiply GB by 1,000. So 5 GB = 5,000 MB. Going the other direction, divide: 3,072 MB ÷ 1,024 = 3 GB (binary). For quick mental math: binary GB to MB, just add three zeros and then add another quarter of the original number. So 4 GB ≈ 4,000 + 1,000 = ~4,096 MB — close enough for most practical purposes.