The complete data storage converter
A data storage converter turns a digital size expressed in one unit into its equivalent in another — for example megabytes into gigabytes, bits into bytes, or gigabytes into gibibytes. This free tool converts across 26 units spanning bits, decimal (SI) bytes and binary (IEC) units, and it computes every result with exact BigInt arithmetic so there is never any floating-point rounding error — even at petabyte, exabyte and yottabyte scale.
Type a value and the conversion happens in real time. You can swap units, see the exact formula and step-by-step working, switch between decimal and binary standards, generate a conversion table, view the result in every unit at once, and save conversions to history or favorites — all privately in your browser. Three built-in calculators also estimate download time, bandwidth usage and total storage requirements.
Quick answers
The most-asked data size questions, answered directly.
How many MB are in 1 GB?
1 GB = 1,000 MB (decimal). 1 GiB = 1,024 MiB (binary).
How many bytes are in 1 MB?
1 MB = 1,000,000 bytes (decimal). 1 MiB = 1,048,576 bytes (binary).
How many bits are in a byte?
1 byte = 8 bits.
How many MB are in 1 TB?
1 TB = 1,000,000 MB = 1,000 GB (decimal).
How many bytes are in 1 GB?
1 GB = 1,000,000,000 bytes (decimal); 1 GiB = 1,073,741,824 bytes (binary).
What is 1 KiB in bytes?
1 KiB (kibibyte) = 1,024 bytes.
How many KB are in 1 MB?
1 MB = 1,000 KB (decimal); 1 MiB = 1,024 KiB (binary).
How fast can a 100 Mbps line download?
100 Mbps ≈ 12.5 MB/s, so a 1 GB file takes about 80 seconds.
How to convert data sizes in 3 steps
Pick your units
Choose the “from” and “to” units — mix bits, decimal bytes (MB, GB) and binary units (MiB, GiB) freely.
Enter a value
Type any number — decimals and scientific notation like 1e9 are supported. The result appears instantly.
Read, copy or save
View the formula, table and every-unit breakdown, then copy, share, download (TXT/CSV), print or star it.
Everything in one converter
Real-time conversion
Results update the instant you type — no convert button, across all 26 data units.
Decimal & binary
Switch between SI (KB, MB, GB) and IEC (KiB, MiB, GiB) standards instantly.
Exact big-number math
BigInt arithmetic means even 1 YB → bytes returns the exact 25-digit integer.
One-click swap
Reverse the conversion direction to check a value both ways in a tap.
Transfer-time calculator
Estimate download / upload time from file size and connection speed.
Storage planner
Total up photos, video, documents and backups to size a drive or plan.
Smart unit search
Find any unit by name, symbol or standard from one search box.
History & favorites
Your last 50 conversions and starred pairs are saved privately in your browser.
Understanding data storage units
Bits, bytes, and the decimal-vs-binary question — explained.
What is a bit?
A bit, short for “binary digit”, is the smallest possible piece of digital information. It can be in only one of two states, written as 0 or 1, off or on, false or true. Computers store and move every kind of data — numbers, text, photos, audio and video — as enormous strings of bits. Eight bits grouped together form a byte. Bits are the natural unit for measuring data-transfer rates, which is why internet plans are advertised in megabits per second (Mbps).
What is a byte?
A byte is a block of 8 bits and is the everyday unit for measuring how much data something takes up. Because 8 bits can represent 2⁸ = 256 distinct values, a single byte is enough to encode one character of basic text. File sizes, memory capacity and storage drives are all measured in bytes and their multiples — kilobytes (KB), megabytes (MB), gigabytes (GB) and terabytes (TB).
Difference between bit and byte
The key distinction is the factor of 8: one byte equals eight bits. Convention also matters — a lower-case “b” means bits and an upper-case “B” means bytes. Network throughput is quoted in bits (Mbps, Gbps), whereas files and disks are quoted in bytes (MB, GB). To turn a connection speed into a realistic download rate, divide the megabits figure by 8: a 1,000 Mbps (1 Gbps) fibre line moves data at up to about 125 MB/s.
Difference between MB and MiB (and GB vs GiB)
MB, GB and TB are decimal units based on powers of 1,000: 1 MB = 1,000,000 bytes and 1 GB = 1,000,000,000 bytes. MiB, GiB and TiB are binary units based on powers of 1,024: 1 MiB = 1,048,576 bytes and 1 GiB = 1,073,741,824 bytes. The binary units, standardised by the IEC in 1998, are always a little larger — a gibibyte is about 7.4% bigger than a gigabyte. Mixing the two is the main reason a drive’s advertised size never quite matches what your operating system reports.
Binary vs decimal storage standards
Two counting systems are used for data. The decimal (SI) system multiplies by 1,000 at each step (kilo, mega, giga) and is used by storage manufacturers, networking equipment and macOS. The binary (IEC) system multiplies by 1,024 at each step (kibi, mebi, gibi) and reflects how memory is actually addressed in hardware; Windows uses binary values but labels them with decimal symbols. This converter keeps both systems explicit so you always know whether you are working in 1,000s or 1,024s.
Why storage manufacturers use decimal units
Hard-drive, SSD and flash makers define capacity in decimal units — 1 GB = 1,000,000,000 bytes — because the SI prefixes “kilo”, “mega” and “giga” officially mean 1,000, 1,000,000 and 1,000,000,000. Decimal figures are also rounder, easier to market and legally standardised. The apparent “shrinkage” you see in Windows is not lost capacity; it is the operating system dividing the same number of bytes by 1,024-based units while still printing the “GB” label.
Cloud storage measurement standards
Major cloud providers — AWS, Google Cloud and Microsoft Azure — bill and report storage in decimal units (GB and TB defined as powers of 1,000), matching the conventions of physical drives. Some services and dashboards still display binary values, so when estimating cost or capacity it pays to confirm whether a quoted “GB” means 1,000,000,000 bytes (decimal) or 1,073,741,824 bytes (binary). This tool lets you check both instantly.
Decimal vs binary at a glance
| Decimal (SI) | Bytes | Binary (IEC) | Bytes |
|---|---|---|---|
| 1 KB | 1,000 | 1 KiB | 1,024 |
| 1 MB | 1,000,000 | 1 MiB | 1,048,576 |
| 1 GB | 1,000,000,000 | 1 GiB | 1,073,741,824 |
| 1 TB | 1,000,000,000,000 | 1 TiB | 1,099,511,627,776 |
Data units explained
- Bit (b)
- The smallest unit of data — a single binary 0 or 1. Eight bits make one byte. Used to measure transfer speed.
- Byte (B)
- Eight bits grouped together; the base unit for file and storage sizes. Stores one character of text.
- Kilobyte (KB)
- One thousand bytes (decimal). A page of plain text is roughly 2–4 KB.
- Megabyte (MB)
- One million bytes (decimal). A high-quality photo or a minute of MP3 audio is a few MB.
- Gigabyte (GB)
- One billion bytes (decimal). About 30 minutes of 1080p video, or ~250 high-res photos.
- Terabyte (TB)
- One trillion bytes (decimal). The typical capacity of a modern hard drive or NAS volume.
- Petabyte (PB)
- 1,000 terabytes. Data-centre and large-enterprise scale; a few PB can hold a major media archive.
- Kibibyte (KiB)
- Binary kilobyte — exactly 1,024 bytes (IEC standard). Used when memory is counted in powers of 1,024.
- Mebibyte (MiB)
- Binary megabyte — 1,048,576 bytes (1,024 KiB). About 4.86% larger than a decimal MB.
- Gibibyte (GiB)
- Binary gigabyte — 1,073,741,824 bytes (1,024 MiB). About 7.4% larger than a decimal GB.
- Megabit (Mb)
- One million bits (decimal). Internet speeds are quoted in megabits per second (Mbps).
- Yottabyte (YB)
- The largest standard decimal unit — 10²⁴ bytes (a septillion). Used for global-internet-scale figures.
Accuracy & precision
Unlike calculators that rely on floating-point numbers, this converter represents every value as an exact rational fraction and performs the maths with arbitrary-precision BigInt integers. That means a conversion like 1 yottabyte to bytes returns the exact value 1,000,000,000,000,000,000,000,000 — not a rounded approximation. You can display anywhere from 0 to 20 decimals, force scientific notation, or read the full exact integer. Decimal (SI) and binary (IEC) standards are kept strictly separate so 1,000 and 1,024 are never confused.
Frequently asked questions
What is a bit?
A bit (binary digit) is the smallest unit of digital information. It holds a single value of either 0 or 1. All digital data — text, images, video and code — is ultimately stored and transmitted as long sequences of bits.
What is a byte?
A byte is a group of 8 bits and is the fundamental unit used to measure file and storage sizes. One byte can represent 256 different values (2⁸), which is enough to store a single character of text such as the letter “A”.
How many bits are in a byte?
There are exactly 8 bits in one byte. So 1 KB (kilobyte) = 8,000 bits, and 1 MB = 8,000,000 bits.
What is the difference between a bit and a byte?
A bit is a single binary digit (0 or 1); a byte is 8 bits. Bits (lower-case b) are normally used to measure data transfer rates such as internet speed — “100 Mbps” means 100 megabits per second. Bytes (upper-case B) are used to measure storage and file sizes. Because a byte is 8 bits, a 100 Mbps connection downloads at most about 12.5 MB/s.
How many MB are in 1 GB?
Using the decimal (SI) standard, 1 GB = 1,000 MB. Using the binary (IEC) standard, 1 GiB = 1,024 MiB. Storage manufacturers and networking use decimal, while many operating systems report binary sizes.
How many bytes are in 1 MB?
1 MB (megabyte) = 1,000,000 bytes using the decimal standard. The binary equivalent, 1 MiB (mebibyte), equals 1,048,576 bytes (1,024 × 1,024).
What is the difference between MB and MiB?
MB (megabyte) is a decimal unit equal to 1,000,000 bytes. MiB (mebibyte) is a binary unit equal to 1,048,576 bytes — about 4.86% larger. The IEC introduced MiB/GiB/TiB in 1998 to remove the ambiguity of using “MB” for both 1,000,000 and 1,048,576 bytes.
What is the difference between GB and GiB?
1 GB = 1,000,000,000 bytes (decimal). 1 GiB = 1,073,741,824 bytes (binary) — roughly 7.4% larger. This is why a “1 TB” drive (1,000,000,000,000 bytes) shows up as about 931 GiB in Windows, which labels GiB as “GB”.
Why does my hard drive show less space than advertised?
Drive makers advertise capacity in decimal units: a “1 TB” drive holds 1,000,000,000,000 bytes. Windows reports size in binary units but labels them “GB”, so it divides by 1,073,741,824 and shows about 931 GB. No space is missing — it is simply the difference between decimal (TB) and binary (TiB/GiB) counting.
Which standard do SSD and hard drive manufacturers use?
Storage manufacturers use the decimal (SI) standard, where 1 GB = 1,000,000,000 bytes and 1 TB = 1,000,000,000,000 bytes. This is the legally standardised definition and is consistent across SSDs, hard drives, USB flash drives and SD cards.
Why do operating systems show different sizes?
Windows calculates sizes in binary (powers of 1024) but displays the binary value with a decimal label (“GB” instead of “GiB”), making files look smaller than the manufacturer’s decimal figure. macOS (since 10.6) and most Linux file managers use decimal units, so they agree with the advertised capacity.
How accurate is this data storage converter?
Every conversion is computed with exact BigInt rational arithmetic, so results carry no floating-point rounding error — even converting 1 yottabyte to bytes returns the exact 25-digit integer. You can also set the displayed precision from 0 to 20 decimals.
How do I convert gigabytes to megabytes?
Multiply the number of gigabytes by 1,000 (decimal). For example, 5 GB × 1,000 = 5,000 MB. For binary units, multiply gibibytes by 1,024: 5 GiB = 5,120 MiB.
How do I convert megabytes to gigabytes?
Divide the number of megabytes by 1,000 (decimal). For example, 2,500 MB ÷ 1,000 = 2.5 GB. For binary units, divide mebibytes by 1,024.
How long does it take to download a file?
Divide the file size in bits by your connection speed in bits per second. A 1 GB file (8,000,000,000 bits) over a 100 Mbps line takes 8,000,000,000 ÷ 100,000,000 = 80 seconds. Use the built-in Download Time calculator to do this instantly.
Why is internet speed measured in megabits but files in megabytes?
Networking has historically measured throughput in bits per second, while storage is measured in bytes. Because 1 byte = 8 bits, a 100 Mbps (megabits) connection transfers at most about 12.5 MB/s (megabytes). Always divide a bit-rate by 8 to estimate the byte-rate.
What is a terabyte (TB)?
1 terabyte = 1,000 gigabytes = 1,000,000 megabytes = 1,000,000,000,000 bytes (decimal). Terabytes are the common unit for modern hard drives, NAS devices and large media libraries. The binary equivalent is the tebibyte (TiB) = 1,099,511,627,776 bytes.
What comes after a terabyte?
After the terabyte come the petabyte (PB, 1,000 TB), exabyte (EB, 1,000 PB), zettabyte (ZB, 1,000 EB) and yottabyte (YB, 1,000 ZB). These large units are used for data-centre, cloud and global-internet scale measurements.
What is a kibibyte (KiB)?
A kibibyte is the binary counterpart of the kilobyte: 1 KiB = 1,024 bytes, defined by the IEC. The “bi” in kibi/mebi/gibi signals a binary (power-of-1024) unit, distinguishing it from the decimal kilobyte (1,000 bytes).
Is a kilobyte 1000 or 1024 bytes?
Strictly, a kilobyte (KB) is 1,000 bytes under the SI standard, and 1,024 bytes is a kibibyte (KiB). Historically “KB” was loosely used for 1,024 bytes, which still causes confusion. This converter keeps the two standards separate so you always know which you are using.
How many photos or songs fit in 1 GB?
As a rough guide, 1 GB holds about 250 high-resolution photos (4 MB each), around 200 MP3 songs (5 MB each), or roughly 30 minutes of 1080p video. Actual counts vary with quality, format and compression.
Can I convert bits to bytes here?
Yes. Select a bit unit (bit, Kb, Mb, Gb…) on one side and a byte unit (B, KB, MB, GB…) on the other. The converter handles the 8× factor automatically, so 1 Mb = 0.125 MB and 1 MB = 8 Mb.
Does this tool work offline and is it private?
Yes. The converter runs entirely in your browser — no value is uploaded to any server. Your conversion history and favorites are stored only in your browser’s local storage, so the tool also works offline once loaded.
What is the largest data unit?
The largest unit in common standards is the yottabyte (YB) = 10²⁴ bytes (decimal), or the yobibyte (YiB) = 2⁸⁰ bytes (binary). Both are supported here and convert with full exact precision.
How much storage do I need for backups?
A good rule of thumb is 2–3× the size of the data you want to protect, to allow for multiple versions and growth. Use the Storage Requirement calculator to total up photos, videos, documents and databases, then add headroom.
Related converters
Unit Converter
Length, weight, temperature, speed, data & more — 12 categories.
Number Converter
Binary, decimal, hexadecimal, octal & Roman numerals.
Fuel Economy Converter
MPG, L/100km and km/L with inverse units.
Angle Converter
Degrees, radians, gradians & turns.
Cooking Converter
Cups, tablespoons, millilitres & more.
Unix Timestamp Converter
Epoch timestamps to dates and back.
Who uses this tool
Developers and DevOps engineers converting payload and log sizes; system and database administrators sizing volumes and backups; cloud and network engineers translating between bits and bytes for throughput and billing; students learning how digital information is measured; and everyday users checking whether a “1 TB” drive really holds what the box claims. Every figure is exact, every standard is explicit, and nothing ever leaves your browser.
Converter Tools
Explore More Tools
Go ad-free & unlock more
- Zero ads, faster focused workflow
- Unlimited history & saved favorites
- Batch convert & CSV export