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SI VS IEC UNITS · BITS & BYTES

SI vs IEC Storage Unit Converter

SI VS IEC UNITS · BITS & BYTES October 2026 12 min read

Compare the decimal SI label on a storage device with the binary IEC value an operating system reports. Free, instant and entirely client-side.

1 GB is 10⁹ bytes, while 1 GiB is 2³⁰ = 1,073,741,824 bytes.

Compare the decimal SI label on a storage device with the binary IEC value an operating system reports.

SI vs IEC unitsExact mathClient-sideWorked examples
1 GB bytes
10^9
1 GiB bytes
2^30
GB vs GiB gap
≈ 7.37%
Client-side
100%
Source: No upload

Quick answer

Compare the decimal SI label on a storage device with the binary IEC value an operating system reports. The calculator applies SI value = q × 1000ᵏ bytes; IEC value = q × 1024ᵏ bytes; gap = 1 − 1000ᵏ/1024ᵏ and shows every intermediate value.

On this page
  1. 1Quick Answer
  2. 2Interactive Calculator
  3. 3SI vs IEC Storage Unit Converter: Technical Breakdown
  4. 4Key Takeaways
  5. 5Developer Statistics
  6. 6Implementation Plans
  7. 7Reference Tables
  8. 8Formulas & How to Use
  9. 9Worked Examples
  10. 10Advanced Education: SI vs IEC Storage Unit Converter
  11. 11Language Playbooks
  12. 12Glossary
  13. 13Mistakes & Pro Tips
  14. 14Use Cases
  15. 15Related Calculators
  16. 16Long-Tail Answers
  17. 17FAQs (14)
  18. 18References

Interactive Calculator

Enter a value — every result updates instantly, in your browser. Free forever, no sign-up.

Private Exact math

SI vs IEC Storage Unit Converter

All inputs are calculated locally with exact integer arithmetic where possible.

Runs in your browser
Quantity Label on the box

Live result

0.909495 TiB

Label matching matters: “GB” is decimal, “GiB” is binary. Never assume they are interchangeable in storage or billing.
SI vs IEC1 TB10.0% gap

SI reading

1 TB

IEC reading

0.909494702 TiB

Ratio SI / IEC

1.099511628

Difference

9.951% more bytes in the IEC label

SI vs IEC Storage Unit Converter: Technical Breakdown

Raw patterns, intermediate values and every step behind the result.

Calculated values and bit-level details
SI reading
1 TB

1 TB = 10^12 bytes

IEC reading
0.909494702 TiB

1 TiB = 2^40 bytes

Ratio SI / IEC
1.099511628
Difference
9.951% more bytes in the IEC label
Total bytes
1,000,000,000,000
Total bits
8,000,000,000,000

Step-by-step calculation

  1. 1Start with 1 TB.
  2. 2Convert to bytes: 1,000,000,000,000.
  3. 3Divide by 1000^4 for TB: 1.000000 TB.
  4. 4Divide by 1024^4 for TiB: 0.909495 TiB.
  5. 5A 1 TB drive is about 0.909 TiB, which is why the operating system reports less than the box label.

Key Takeaways

The 30-second version — the exact answers Google loves to feature.

  • 11 GB is 10⁹ bytes, while 1 GiB is 2³⁰ = 1,073,741,824 bytes.
  • 2A 1 TB drive contains about 0.909 TiB, which is why the reported capacity looks smaller.
  • 3The IEC prefixes are kibi, mebi, gibi, tebi and pebi, abbreviated KiB, MiB, GiB, TiB and PiB.
  • 4The difference is a unit convention, not missing storage or a manufacturing defect.
  • 51 GB is 10^9 bytes; 1 GiB is 2^30 bytes, or 1,073,741,824 bytes.

Developer Statistics & Reference Facts

Numbers worth remembering. Use them to sanity-check inputs, ranges and boundary values before shipping code.

1 GB bytes
10^9
1 GiB bytes
2^30
GB vs GiB gap
≈ 7.37%
Client-side
100%
Source: No upload
Integer math
Exact
Source: BigInt
TB vs TiB gap
≈ 9.95%

Implementation Plans Compared: Which Workflow Fits?

Three practical ways to use this calculator. Match the plan to the risk level of your project, then follow its safeguards.

Quick check

Best for: Everyday conversions, homework and code reviews

  • Method: Paste the value into the calculator and read the headline si vs iec units result.
  • Precision: Exact for integers; floating-point displays are rounded for readability.
  • Safeguards: Cross-check one boundary value and one ordinary value before trusting the pattern.
Recommended

Production implementation

Best for: Shipping code that parses or emits binary data

  • Method: Use fixed-width integer types, explicit byte order and the same width on both sides of the conversion.
  • Precision: Match the exact bit width and signedness used by the file format or protocol.
  • Safeguards: Add unit tests for 0, 1, −1, minimum, maximum and one-past-maximum values.

Protocol / test vector

Best for: Firmware, network protocols and interoperability work

  • Method: Reproduce the published test vector in the calculator, then compare the raw hex byte-for-byte.
  • Precision: Use the protocol’s declared width, polynomial, endianness and initial/final XOR values.
  • Safeguards: Keep a golden vector in the repository and run it in CI on every change.

Quick Reference Tables

Widths, ranges, boundary values and language types — the lookup tables you will come back to.

Decimal vs binary prefixes

Decimal (SI)BytesBinary (IEC)Bytes
KB10^3KiB2^10 = 1,024
MB10^6MiB2^20 = 1,048,576
GB10^9GiB2^30 = 1,073,741,824
TB10^12TiB2^40 = 1,099,511,627,776

Formulas & How to Use This Calculator

Core relationship

SI value = q × 1000ᵏ bytes; IEC value = q × 1024ᵏ bytes; gap = 1 − 1000ᵏ/1024ᵏ

Verification

1. Normalize the input to the stated width. 2. Apply the operation with explicit masking. 3. Compare the decimal, hex and binary readings. 4. Reverse the operation or repeat it with a boundary value.

How to use — step by step

  1. Choose the bit width or input format that matches your data.
  2. Enter the value (or values) in the input panel. Results update as you type.
  3. Read the headline result, then check the decimal, hex and binary rows for consistency.
  4. Open the technical breakdown to inspect the bit groups, mask or intermediate values.
  5. Compare one boundary value (0, 1, minimum or maximum) to confirm the behavior.
  6. Copy the result into your code or test vector, and keep the width and byte order documented.

Worked Examples

Real numbers and raw bits, fully worked — copy the pattern for your own code or protocol.

1 TB drive in TiB

Inputs

1 TB (SI)

Math

10¹² ÷ 2⁴⁰

Result

≈ 0.90949 TiB

1 TiB in TB

Inputs

1 TiB (IEC)

Math

2⁴⁰ ÷ 10¹²

Result

≈ 1.09951 TB

1 GB in GiB

Inputs

1 GB

Math

10⁹ ÷ 2³⁰

Result

≈ 0.93132 GiB

Advanced Education: SI vs IEC Storage Unit Converter

Beyond the calculator — the mental models, language rules and edge cases professionals use.

Bytes, words and the memory model

Memory is byte-addressed. A 32-bit integer occupies four consecutive addresses, and endianness decides which byte goes first. Big-endian stores the most significant byte at the lowest address; little-endian stores the least significant byte there. The SI vs IEC Storage Unit Converter shows the byte sequence for the selected width and order. A hex dump is a sequence of bytes, not a number, so you must know both the width and the order before you can read it. When a protocol says “32-bit field”, it usually also says “network byte order” or “little-endian”; if it does not, the format is underspecified.

Why x86 is little-endian and the network is big-endian

x86 and most ARM implementations are little-endian because the least significant byte is available first for narrower loads and arithmetic. Early network protocols standardized on big-endian, which is why TCP/IP headers use network byte order and why functions are named htons and htonl. The mismatch is a constant source of bugs when a struct is sent directly over a socket. The SI vs IEC Storage Unit Converter lets you compare both orders for the same value. Never transmit a raw struct without a defined serialization; padding and endianness make the layout platform-dependent.

Byte swapping without changing bits

A byte swap reverses the order of whole bytes. The bits inside each byte keep their positions. For 0x12345678, swapping gives 0x78563412, and the byte sequence changes from 12 34 56 78 to 78 56 34 12. C provides __builtin_bswap16/32/64 on GCC and Clang; Java has Integer.reverseBytes; Python’s int.from_bytes accepts a byteorder argument. The SI vs IEC Storage Unit Converter prints both the bytes and the numeric value before and after the swap. Do not confuse a byte swap with a bit reversal, which is a different operation used in some CRCs and DSP algorithms.

Hex arrays, text and encoding

A hex byte array is a human-readable representation of binary data. Two hex digits represent one byte, so the string length is twice the byte count plus any separators. Text becomes bytes through an encoding: ASCII uses one byte per character, UTF-8 uses one to four, and UTF-16 uses two or four. The SI vs IEC Storage Unit Converter converts between text and bytes using UTF-8. If you paste a hex dump with an odd number of digits, pad on the left with a zero only when the field is known to be a whole number of bytes; otherwise the missing digit is a data error.

Integer serialization and schema design

Serializing an integer means fixing its width, signedness and byte order. A schema that says “int” is ambiguous across languages; say “signed 32-bit little-endian” instead. The SI vs IEC Storage Unit Converter normalizes the value to the chosen width, splits it into bytes and prints the sequence. For negative values, two’s complement determines the pattern. For variable-length formats such as protobuf or varints, the width is not fixed and the encoding rules are different; do not apply fixed-width byte splitting to them. Document the schema next to the data, not only in the code that produced it.

Deserialization and validation

Reading an integer from bytes is the inverse operation, but it needs more validation. Check the byte count, reject unsupported widths, and decide whether a short buffer is an error or should be zero-padded. The SI vs IEC Storage Unit Converter supports one to eight bytes and both byte orders. For signed values, apply the sign rule after assembling the unsigned value. If the field is part of a larger struct, account for padding and alignment; a raw memcpy of the struct is not portable. Fuzz the parser with truncated, oversized and all-ones inputs before trusting it with untrusted data.

Data size units and the 1000 versus 1024 confusion

SI prefixes use powers of 1000: kB, MB, GB, TB. IEC prefixes use powers of 1024: KiB, MiB, GiB, TiB. A 1 TB drive holds 10^12 bytes, which is about 931 GiB. Operating systems have historically displayed binary values with decimal labels, which is why the same drive shows different numbers in different tools. The SI vs IEC Storage Unit Converter converts between the units and shows the exact byte count. In APIs, store bytes and let the client format them. If you must store a human-readable size, store the unit alongside the number.

Memory addresses, offsets and alignment

An address is a byte-granular location. An offset is the distance from a base address. For an array, the address of element i is base + i × sizeof(element). For a struct, each member has a fixed offset chosen by the compiler to satisfy alignment. The SI vs IEC Storage Unit Converter converts between the components and prints the hex address. Pointer arithmetic in C and C++ scales by the pointed-to type, so adding 1 to an int* advances four bytes on a typical platform. Use a byte pointer or an explicit offset when you need exact control, and check for overflow in the address calculation.

Language & Platform Playbooks

The same bit pattern behaves differently in every language. Here is how to adapt the conversion safely.

C / C++

Use fixed-width types from <stdint.h> and make the width part of the type: uint32_t, int16_t, uint64_t. For si vs iec storage unit converter, keep the value unsigned while manipulating bits, then cast only at the boundary. Enable -Wall -Wextra -Wconversion and test with UBSan to catch shifts and signed overflow.

Java / Kotlin

Java’s int and long are 32 and 64-bit two’s complement; byte and short are promoted to int in expressions. Use Integer.toUnsignedLong, Long.toUnsignedString and Integer.reverseBytes when si vs iec storage unit converter crosses an unsigned or byte-order boundary. Kotlin’s unsigned types are experimental but useful for parsing.

Python

Python integers are arbitrary precision, so mask to the target width after every operation: value & ((1 << width) - 1). Use int.from_bytes and int.to_bytes with an explicit byteorder for si vs iec storage unit converter, and use struct for fixed binary layouts. Never rely on the default byte order in portable code.

JavaScript / TypeScript

JavaScript bitwise operators coerce to 32-bit signed integers. Use BigInt for 64-bit si vs iec storage unit converter, mask with BigInt.asUintN, and remember that JSON cannot serialize BigInt. DataView is the reliable way to read and write float and integer fields in an ArrayBuffer.

Rust

Rust makes width and signedness explicit: u8, i32, u64. Use wrapping_*, checked_* or overflowing_* for arithmetic, from_le_bytes and from_be_bytes for byte order, and count_ones, leading_zeros and trailing_zeros for bit operations. The SI vs IEC Storage Unit Converter results map directly to these methods.

Go

Go’s integer types have defined widths; int is platform-dependent, so use int32 or int64 when the width matters. Use encoding/binary with an explicit byte order for si vs iec storage unit converter, and math/bits for population count, leading zeros and rotations. Go panics on some out-of-range shifts, so validate the amount.

C# / .NET

C# has checked and unchecked contexts; use unchecked explicitly when wraparound is intended. Convert.ToInt32 and BitConverter respect the platform’s endianness, so use BinaryPrimitives.ReadInt32LittleEndian or the big-endian variant for si vs iec storage unit converter. System.Numerics.BitOperations provides popcount and zero counts.

Embedded / bare metal

On a microcontroller, confirm the register width and access size before writing. Use volatile pointers for memory-mapped registers, mask reserved bits, and respect write-1-to-clear semantics. For si vs iec storage unit converter, keep the arithmetic in the register’s native width and avoid 64-bit division on small cores unless the library is available.

Glossary: Key Terms Explained

Decimal unit
A unit based on powers of 1000, such as KB, MB, GB and TB.
Binary unit
A unit based on powers of 1024, such as KiB, MiB, GiB and TiB.
GiB
1,073,741,824 bytes, equal to 1.073741824 GB.
Drive marketing
Storage vendors usually quote decimal capacities because the numbers look larger.
Bit
A binary digit: 0 or 1. Bits are grouped into bytes, words and registers.
Byte
Eight bits. A byte is the smallest addressable unit on most CPUs and the usual unit for file sizes.
Word
The natural register width of a CPU. On modern 64-bit systems a word is usually 64 bits, though C’s int is often 32 bits.
MSB / LSB
Most significant bit and least significant bit. The MSB carries the largest positional weight and is the sign bit in signed integers.

Common Mistakes & Pro Tips

Mistakes that break conversions

  • Mixing widths in one expression: a 32-bit value read as 16 bits silently loses the high half.
  • Assuming decimal text is already a raw bit pattern; use the correct input format and radix.
  • Forgetting that signed right shifts and signed overflow are implementation-defined in C and C++.
  • Comparing floating-point results with exact equality instead of a magnitude-aware tolerance.

Pro tips for production code

  • Write the width and signedness into type names or variable names so the reader cannot misread them.
  • Add boundary vectors to CI: 0, 1, −1, minimum, maximum and one-past-maximum.
  • When debugging, print the raw hex first; decimal formatting hides byte-order mistakes.
  • Prefer standard library conversion functions over hand-rolled parsers for untrusted input.

Who Should Use This Calculator?

  • ▸ Code review: confirm that a constant, mask or serialized field matches the specification.
  • ▸ Test-vector generation: produce expected hex and binary values for unit tests.
  • ▸ Debugging: decode a register dump, packet capture or file header without writing a script.
  • ▸ Teaching: show the intermediate steps behind a representation change.

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People Also Search For

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Frequently Asked Questions (14)

Long-tail answers: each question targets a real Google search about si vs iec storage unit converter — click to expand.

Showing 14 of 14 answers.

What is the difference between GB and GiB?
1 GB is 10^9 = 1,000,000,000 bytes. 1 GiB is 2^30 = 1,073,741,824 bytes. A GiB is about 7.37% larger than a GB. Storage vendors usually quote GB, while operating systems and memory sizes often use GiB.
Which unit should I use in an API?
Use bytes for exact storage and transfer sizes, and state whether a human-readable label is decimal or binary. Avoid ambiguous “MB” in schemas. If you must use a prefix, write “MB” for 10^6 and “MiB” for 2^20, and include the raw byte count alongside it.
Is the SI vs IEC Storage Unit Converter exact?
Integer paths in the SI vs IEC Storage Unit Converter use BigInt arithmetic, so widths up to 64 bits are exact. Floating-point displays are rounded to 9 significant digits for binary32 and 17 for binary64, which is enough to round-trip the underlying value. Always keep the raw hex or binary pattern when you need a byte-exact result.
Can I use the SI vs IEC Storage Unit Converter for 64-bit values?
Yes. Choose the 64-bit width where the control exists. The engine uses BigInt and explicitly masks to 64 bits, so values such as 0xFFFFFFFFFFFFFFFF and 18,446,744,073,709,551,615 are handled without JavaScript Number precision loss. For 128-bit work, use a language with native 128-bit integers or a big-integer library.
Why does the SI vs IEC Storage Unit Converter show a different result from my code?
Check four things in order: the declared bit width, signedness, byte order and whether your language promoted the operands. C and C++ promote small integer types to int before arithmetic, Java uses 32-bit int by default, and Python integers are arbitrary precision. A mismatch in any one of those rules changes the expected pattern.
What is a safe way to test si vs iec storage unit converter results?
Use boundary values: 0, 1, −1, the minimum, the maximum, one past the maximum and the all-ones pattern. Compare the decimal, hexadecimal and binary outputs, then repeat the calculation in your target language. For protocol work, add the published test vector to CI so a future refactor cannot silently change the byte layout.
Does the SI vs IEC Storage Unit Converter send my data anywhere?
No. The calculation runs entirely in your browser with client-side JavaScript. Nothing is uploaded, logged or stored by the tool. That makes it safe for proprietary register maps, protocol captures and customer data, although you should still follow your organization’s data-handling policy.
Why do I see an error or an empty result in the SI vs IEC Storage Unit Converter?
The most common causes are an empty required field, a digit that is invalid for the selected base, a value outside the selected width, or a bit position at or above the width. Read the red message under the result: it names the field and the allowed range. Reset the example value if you want a known-good starting point.
What is the si vs iec storage unit converter used for?
Compare the decimal SI label on a storage device with the binary IEC value an operating system reports. Developers use it to check a conversion before shipping code, to reproduce a protocol test vector, or to explain a bit pattern in a code review. The page shows the headline result first, then the intermediate values so you can verify each step rather than trusting a black box.
How do I read the si vs iec storage unit converter result?
Start with the headline card: it shows the primary answer in the unit or base you selected. The rows below list the same result in decimal, hexadecimal and binary where applicable, plus the mask, width or field details. The technical breakdown then shows the bit groups, intermediate values and a short explanation of each step.
What formula does the si vs iec storage unit converter use?
SI value = q × 1000ᵏ bytes; IEC value = q × 1024ᵏ bytes; gap = 1 − 1000ᵏ/1024ᵏ The calculator evaluates that relationship with the values you enter and prints the substitution. For width-dependent operations it masks to the selected number of bits, so the result matches fixed-width hardware rather than unbounded integer arithmetic.
What is a common mistake when using si vs iec storage unit converter?
The most common mistake is mixing widths: entering a 32-bit value but reading it as 16 bits, or assuming a decimal literal is already a raw bit pattern. Choose the width first, then the input format, then enter the value. The result rows always state the width so you can catch a mismatch.
How do I verify a si vs iec storage unit converter result by hand?
Repeat the operation with the smallest possible example, such as 0, 1 or a single set bit, and check the pattern against the formula. Then try a boundary value and confirm the wrap or saturation behavior. Finally, compare the hex and binary rows; if they disagree with the decimal row, the input format or width is probably wrong.
Does the si vs iec storage unit converter work offline?
Once the page has loaded, all calculations run in the browser and do not require a network request. You can keep the tab open while you work offline. The page itself is served from the web, so the first load needs a connection, but your values are never transmitted to a server.

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