What is the difference between KB and KiB?

KB (kilobyte) = 1,000 bytes in the decimal (SI) system used by storage manufacturers and network providers. KiB (kibibyte) = 1,024 bytes in the binary (IEC) system used by operating systems. The same confusion applies to MB vs MiB, GB vs GiB, etc. A 1 TB hard drive contains 1,000,000,000,000 bytes but Windows reports it as ~931 GiB.

How many bytes are in a gigabyte?

In decimal (SI): 1 GB = 1,000,000,000 bytes (10⁹). In binary (IEC): 1 GiB = 1,073,741,824 bytes (2³⁰). The decimal definition is used by hard drives and network speeds. The binary definition is used by operating systems like Windows, Linux, and macOS.

How do you convert Mbps to MB/s?

Divide megabits per second by 8 to get megabytes per second. Example: 100 Mbps ÷ 8 = 12.5 MB/s. This is because 1 byte = 8 bits. So a 100 Mbps internet connection can theoretically download at 12.5 MB/s.

Why does my 1 TB hard drive show 931 GB in Windows?

Hard drive manufacturers use decimal (1 TB = 10¹² bytes = 1,000,000,000,000 bytes). Windows displays storage in binary GiB: 10¹² ÷ 1024³ = 931.32 GiB. The drive is not missing any space — it's just a different measurement unit. Linux and macOS show the same discrepancy.

A petabyte (PB) = 1,000 terabytes = 10¹⁵ bytes in decimal. In binary, 1 PiB (pebibyte) = 1,024 TiB = 2⁵⁰ bytes. To put it in perspective: 1 PB could store about 500 billion pages of standard print text, or 11,000 4K movies.

Data Converter

Our Data Converter handles every common digital storage and data transfer unit conversion. Enter a value in any field — bits, bytes, kilobytes, megabytes, gigabytes, terabytes, or petabytes — and see the equivalent in all other units instantly. Toggle between decimal units (1 KB = 1,000 bytes, as used by hard drive manufacturers and network speeds) and binary units (1 KiB = 1,024 bytes, as used by operating systems like Windows, Linux, and macOS). Perfect for developers, IT professionals, students, and anyone working with file sizes or storage capacities.

star 4.8 (976 ratings)

calendar_today Updated: April 2026

New

Enter Value

Value

From Unit

decimal_increase

Decimal (SI)

Powers of 1,000

bits (b)

Bytes (B)

memory

Binary (IEC)

Powers of 1,024

bits (b)

Bytes (B)

KiB

MiB

GiB

TiB

PiB

Input Values

Value

From Unit

bit (b)

Byte (B)

Kilobyte (KB)

Megabyte (MB)

Gigabyte (GB)

Terabyte (TB)

compare_arrows Decimal vs Binary

DecimalUnitBinary

1,000 B KB / KiB 1,024 B

10⁶ B MB / MiB ~1.049M B

10⁹ B GB / GiB ~1.074G B

10¹² B TB / TiB ~1.100T B

10¹⁵ B PB / PiB 2⁵⁰ B

speed Mbps → MB/s Reference

10 Mbps 1.25 MB/s

100 Mbps 12.5 MB/s

1 Gbps 125 MB/s

2.5 Gbps 312.5 MB/s

10 Gbps 1,250 MB/s

Formula: Mbps ÷ 8 = MB/s

lightbulb Quick Tips

•1 TB drive shows ~931 GiB in Windows — not missing space!
•Hard drives use decimal; OS reports binary
•RAM is always binary (GiB)
•Click any result to copy to clipboard
•Divide internet speed (Mbps) by 8 for MB/s

How to Use This Calculator

Enter a Value

Type any number in any data unit field — bits, bytes, KB, MB, GB, TB, or binary units (KiB, MiB, GiB, TiB).

See All Conversions

All other unit fields update instantly as you type. No need to click calculate.

Switch Standards

Toggle between Decimal (SI) and Binary (IEC) to see how the same data is measured under each standard.

Copy Any Value

Click any result field to copy its value for use in your project or documentation.

The Formula

Two standards exist: decimal (SI) uses powers of 1,000 — used by hard drive manufacturers, network providers, and file transfer speeds. Binary (IEC) uses powers of 1,024 — used by operating systems to report RAM, file sizes, and storage. This is why a '1 TB' drive shows as ~931 GiB in Windows.

1 KB = 1,000 bytes (decimal) | 1 KiB = 1,024 bytes (binary)

lightbulb Variables Explained

bit (b) Smallest unit — 0 or 1 (binary digit)
byte (B) 8 bits — smallest addressable memory unit
KB / KiB Kilobyte = 1,000 B (decimal) | Kibibyte = 1,024 B (binary)
MB / MiB Megabyte = 1,000,000 B | Mebibyte = 1,048,576 B
GB / GiB Gigabyte = 10⁹ B | Gibibyte = 1,073,741,824 B
TB / TiB Terabyte = 10¹² B | Tebibyte = 1,099,511,627,776 B
PB / PiB Petabyte = 10¹⁵ B | Pebibyte = 2⁵⁰ B

tips_and_updates Pro Tips

Hard drives are advertised in decimal GB/TB; OS reports in binary GiB/TiB — a '1 TB' drive shows ~931 GiB in Windows

Internet speeds (Mbps, Gbps) use decimal bits — divide Mbps by 8 to get MB/s download speed

RAM is always binary: 8 GiB = 8,589,934,592 bytes

1 byte = 8 bits. So 100 Mbps = 12.5 MB/s (divide by 8)

SSD and NVMe storage use decimal like HDDs — expect ~7% less space than advertised when formatted

Two standards define data units: Decimal (SI) uses powers of 1,000 — 1 KB = 1,000 bytes. Binary (IEC) uses powers of 1,024 — 1 KiB = 1,024 bytes. The confusion between these standards is why a '1 TB' hard drive appears as ~931 GiB in Windows. Our converter shows both simultaneously.

1 byte = 8 bits. 1 KB = 1,000 bytes (decimal) or 1 KiB = 1,024 bytes (binary). 1 MB = 1,000 KB. 1 GB = 1,000 MB = 1 billion bytes. 1 TB = 1,000 GB = 1 trillion bytes. To convert Mbps to MB/s: divide by 8.

Frequently Asked Questions

Related Tools

View all Converters View all arrow_forward

calculate