Understanding Digital Storage Conversions
Digital storage is measured in bytes and multiples of bytes. Two systems coexist: decimal (KB, MB, GB using 1,000) and binary (KiB, MiB, GiB using 1,024). This converter supports both so you can convert KB to MB, GB to TB, or understand why a "1 TB" drive shows as 931 GB in your OS.
How Digital Storage Conversion Works
All digital storage units are defined relative to the byte. To convert between any two units, the value is first expressed in bytes, then divided by the target unit's byte equivalent. The general formula is:
Result = Value × (source unit in bytes) ÷ (target unit in bytes)
Decimal (SI) units use powers of 1,000: 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes, 1 GB = 1,000,000,000 bytes. Hard drive and SSD manufacturers use these when they label capacity (e.g. "500 GB").
Binary (IEC) units use powers of 1,024: 1 KiB = 1,024 bytes, 1 MiB = 1,024² bytes, 1 GiB = 1,024³ bytes. Operating systems (Windows, macOS, Linux) often report file and drive sizes in binary units, which is why a "1 TB" (1,000 GB decimal) drive displays as about 931 GiB.
Decimal vs Binary: Every Unit Explained
The exact relationship of each unit to one byte. Use this reference when converting KB to MB, MB to GB, or when comparing drive labels (decimal) to what your OS shows (binary).
Byte (B)
Factor: 1 (base unit)
The fundamental unit of digital storage — typically one character (letter or number) in plain text. Eight bits make one byte. File sizes, memory, and storage are all measured in bytes and its multiples.
Kilobyte (KB) — Decimal
Factor: 1 KB = 1,000 bytes
SI prefix "kilo" means 1,000. Used by storage manufacturers and in networking (e.g. kbps). A short plain-text email is often 1–5 KB. Historically "kilobyte" was used for 1,024 bytes, causing the decimal vs binary confusion.
Kibibyte (KiB) — Binary
Factor: 1 KiB = 1,024 bytes
IEC binary prefix: "ki" = 2¹⁰ = 1,024. Used in OS and software when reporting file sizes. 1 KiB is about 2.4% larger than 1 KB. Adopted to end the ambiguity between "1 KB = 1000 or 1024?"
Megabyte (MB) — Decimal
Factor: 1 MB = 1,000,000 bytes
One million bytes. Common in consumer labels: "16 MB/s" transfer, "500 MB" data plan. A typical MP3 song is 3–5 MB. Converting MB to GB: divide by 1,000.
Mebibyte (MiB) — Binary
Factor: 1 MiB = 1,048,576 bytes (1,024²)
Binary megabyte. RAM and many OS tools report in MiB. 1 MiB ≈ 1.049 MB. When you see "512 MiB" in a system monitor, that's 512 × 1,024 × 1,024 bytes.
Gigabyte (GB) — Decimal
Factor: 1 GB = 1,000,000,000 bytes
One billion bytes. The standard for drive and SSD capacity labels. A "256 GB" phone or "2 TB" SSD uses decimal: 256 × 10⁹ and 2 × 10¹² bytes respectively.
Gibibyte (GiB) — Binary
Factor: 1 GiB = 1,073,741,824 bytes (1,024³)
Binary gigabyte. Windows and many Linux tools show drive free space in GiB. 1 TB (decimal) = 1,000 GB = about 931 GiB. That's why your "1 TB" drive doesn't show 1,000 GB in the OS.
Terabyte (TB) & Tebibyte (TiB)
Factor: 1 TB = 10¹² bytes; 1 TiB = 1,024⁴ bytes
Terabyte = 1,000 GB (decimal). Tebibyte = 1,024 GiB (binary). Used for large drives, backups, and data centers. Converting TB to GB: multiply by 1,000. 1 TB ≈ 0.909 TiB.
Petabyte (PB) & Pebibyte (PiB)
Factor: 1 PB = 10¹⁵ bytes; 1 PiB = 1,024⁵ bytes
Petabyte = 1,000 TB. Used in big data, cloud storage, and scientific datasets. 1 PB is about 909 TiB. Exabyte (EB) and larger units follow the same decimal (1,000) pattern.
Common Digital Storage Conversions at a Glance
Quick reference for the conversions people search for most: convert KB to MB, MB to GB, GB to TB, and bytes to human-readable sizes.
| From | To | Formula | Example |
|---|---|---|---|
| Kilobytes (KB) | Megabytes (MB) | KB ÷ 1,000 | 2,500 KB = 2.5 MB |
| Megabytes (MB) | Gigabytes (GB) | MB ÷ 1,000 | 4,096 MB = 4.096 GB |
| Gigabytes (GB) | Terabytes (TB) | GB ÷ 1,000 | 1,500 GB = 1.5 TB |
| Kibibytes (KiB) | Mebibytes (MiB) | KiB ÷ 1,024 | 2,048 KiB = 2 MiB |
| Gibibytes (GiB) | Tebibytes (TiB) | GiB ÷ 1,024 | 1,024 GiB = 1 TiB |
| Terabytes (TB, decimal) | Gibibytes (GiB, binary) | 1 TB ≈ 931.32 GiB | 1 TB drive ≈ 931 GiB in OS |
Why a "1 TB" Drive Shows as 931 GB
This is the most common source of confusion in digital storage conversion. Manufacturers label drives using decimal units: 1 TB = 1,000,000,000,000 bytes = 1,000 GB. Operating systems often report capacity in binary units: 1 GiB = 1,073,741,824 bytes. So the same number of bytes is expressed differently.
1 TB (decimal) = 1,000,000,000,000 bytes ÷ 1,073,741,824 bytes/GiB ≈ 931.32 GiB
The "missing" space isn't lost — it's a unit difference, not a formatting overhead.
When you buy a 1 TB SSD, you get one trillion bytes. Your OS divides that by 1,024³ to show Gibibytes, so you see about 931 GiB. Use this converter to switch between decimal (manufacturer) and binary (OS) units anytime.
The History of Digital Storage Units
Bits, Bytes, and the Kilobyte Confusion
The byte was standardized as 8 bits in the 1950s–60s. Early computer scientists used powers of 2 (1,024, 1,048,576) because memory is addressed in binary. So "1 kilobyte" was taken to mean 1,024 bytes — close enough to 1,000 for rough talk, but not the same. That dual meaning caused decades of ambiguity: is 1 KB = 1,000 or 1,024?
The IEC Binary Prefixes: KiB, MiB, GiB
In 1998 the IEC (International Electrotechnical Commission) introduced binary prefixes: kibi (Ki), mebi (Mi), gibi (Gi), tebi (Ti), pebi (Pi). One Kibibyte (KiB) = 1,024 bytes; one Mebibyte (MiB) = 1,024² bytes; one Gibibyte (GiB) = 1,024³ bytes. This lets "kilobyte" (KB) mean strictly 1,000 bytes (SI) and "kibibyte" (KiB) mean 1,024 bytes. Linux and many professional tools use KiB/MiB/GiB; Windows still often shows "KB/MB/GB" but uses 1,024 under the hood for file sizes.
Why Drive Makers Use Decimal
Hard drive and SSD manufacturers market capacity in decimal (1 TB = 10¹² bytes) for consistency with SI and because the number looks larger (1,000 GB vs ~931 GiB). Storage industry standards (e.g. JEDEC for flash) also use decimal for capacity. So when you convert MB to GB or GB to TB for drive specs, use 1,000; when interpreting OS or binary-oriented tools, use 1,024 or this converter's binary units.
Real-World Digital Storage References
Approximate sizes to calibrate your intuition when converting KB to MB, MB to GB, or planning storage.
Documents & Text
- Plain text page: ~2–4 KB
- PDF (few pages): 100–500 KB
- Word doc (with images): 1–5 MB
- E-book: 1–10 MB
Media
- MP3 song: 3–5 MB
- Photo (12 MP): 3–6 MB
- 1 min 1080p video: ~100–200 MB
- 1 hr 1080p video: ~4–8 GB
Devices & Drives
- RAM (typical laptop): 8–32 GiB
- Smartphone storage: 64–256 GB
- SSD (consumer): 256 GB – 2 TB
- External HDD: 1–8 TB
Large Scale
- Data center rack: 1–10 PB
- Big data / cloud: 100 PB – 1 EB+
Digital Storage Conversion FAQ
? How many MB are in a GB?
In decimal (SI): 1 GB = 1,000 MB. So to convert GB to MB, multiply by 1,000 (e.g. 2 GB = 2,000 MB). In binary: 1 GiB = 1,024 MiB. This converter supports both; choose the unit that matches your source (e.g. drive label = decimal, many OS tools = binary).
? What is the difference between KB and KiB?
KB (kilobyte) is decimal: 1 KB = 1,000 bytes. KiB (kibibyte) is binary: 1 KiB = 1,024 bytes. So 1 KiB is about 2.4% larger than 1 KB. Use KB when matching manufacturer or network specs; use KiB when matching OS or software that uses 1,024-based units.
? Why does my 1 TB drive only show 931 GB?
Manufacturers use decimal: 1 TB = 1,000 GB = 10¹² bytes. Your operating system often reports in binary: 1 GiB = 1,024³ bytes. So 1 trillion bytes ÷ 1,024³ ≈ 931.32 GiB. No space is missing — it's a unit conversion. Use this tool to convert TB to GiB and you'll see the same result.
? How do I convert bytes to KB or MB?
For decimal: divide bytes by 1,000 for KB, by 1,000,000 for MB, by 1,000,000,000 for GB. For binary: divide by 1,024 for KiB, 1,024² for MiB, 1,024³ for GiB. This converter accepts any unit and does the math; enter your value and select "Byte" as the source unit, then choose the target unit.