Converter

Data Storage Converter

Convert between bits, bytes, KB, MB, GB, TB, and PB with both binary (1024) and decimal (1000) values shown side by side.

Quick Answer

1 GB = 1,000 MB (decimal) or 1 GiB = 1,024 MiB (binary). 1 byte = 8 bits. A 1 TB drive shows as ~931 GiB in your OS. Enter a value below to see both systems.

Convert Data Size

Enter a value and select a unit. Both binary and decimal equivalents will be shown.

Decimal (SI) — base 1000

Bits (b)8,000,000,000
Bytes (B)1,000,000,000
Kilobytes (KB)1,000,000
Megabytes (MB)1,000
Gigabytes (GB)1
Terabytes (TB)0.001
Petabytes (PB)0.000001

Binary (IEC) — base 1024

Bits (b)8,000,000,000
Bytes (B)1,000,000,000
Kibibytes (KiB)976,562.5
Mebibytes (MiB)953.6743
Gibibytes (GiB)0.9313225746
Tebibytes (TiB)0.0009094947
Pebibytes (PiB)0.0000008882

Common File & Storage Sizes

ItemTypical Size
Text email (no attachments)~10 KB
MP3 song (4 min)~4 MB
HD photo (JPEG)~5 MB
HD movie (1080p, 2 hrs)~4-5 GB
4K movie (2 hrs)~15-20 GB
Typical SSD256 GB - 2 TB
Cloud storage (free tier)5-15 GB

About This Tool

The Data Storage Converter lets you instantly convert between seven common data size units, showing both decimal (SI) and binary (IEC) values side by side. This dual display helps you understand the discrepancy between advertised storage sizes and what your operating system reports.

Decimal vs Binary: Why It Matters

Storage manufacturers use decimal prefixes (1 KB = 1,000 bytes, 1 GB = 1,000,000,000 bytes) because it is the standard set by the International System of Units. Operating systems historically used binary prefixes (1 KB = 1,024 bytes) because computers work in powers of two. To resolve this ambiguity, the IEC introduced binary prefixes: kibibyte (KiB), mebibyte (MiB), gibibyte (GiB), etc. Modern macOS uses decimal units, while Windows still shows binary values with decimal labels.

Bits vs Bytes in Internet Speeds

Internet service providers advertise speeds in megabits per second (Mbps), while file sizes are measured in megabytes (MB). Since 1 byte = 8 bits, you need to divide your internet speed by 8 to get the approximate download speed in megabytes per second. A 100 Mbps connection downloads at roughly 12.5 MB/s under ideal conditions.

Modern Storage Scales

Consumer storage has grown dramatically: smartphones now offer 128 GB to 1 TB, laptops typically include 256 GB to 2 TB SSDs, and cloud storage plans range from 100 GB to multiple TB. At enterprise scale, data is measured in petabytes (PB) and exabytes (EB). Understanding these units helps when comparing plans, estimating backup needs, and planning data migrations.

Frequently Asked Questions

What is the difference between GB and GiB?
A gigabyte (GB) uses the decimal system: 1 GB = 1,000,000,000 bytes (10⁹). A gibibyte (GiB) uses the binary system: 1 GiB = 1,073,741,824 bytes (2³⁰). Hard drive manufacturers use GB (decimal), while operating systems like Windows often display sizes in GiB but label them as GB. This is why a 1 TB hard drive shows as ~931 GB in Windows — it is actually showing 931 GiB.
Why does my hard drive show less space than advertised?
Hard drive manufacturers measure in decimal units (1 TB = 1,000,000,000,000 bytes), while operating systems measure in binary units (1 TiB = 1,099,511,627,776 bytes). A 1 TB drive has exactly 1 trillion bytes, but Windows reports this as 931 GiB (which it labels as GB). Additionally, some space is reserved for the file system and formatting overhead. The drive has the right amount of bytes — the discrepancy is purely a labeling issue.
How many megabytes are in a gigabyte?
In the decimal system (used by storage manufacturers and network providers): 1 GB = 1,000 MB. In the binary system (used by operating systems internally): 1 GiB = 1,024 MiB. For most everyday purposes, using 1 GB = 1,000 MB is close enough and matches what you see on product labels and in most software. The 2.4% difference between 1,000 and 1,024 becomes significant at larger scales (TB and PB).
What is the difference between bits and bytes?
A bit (b) is the smallest unit of digital information: a single 0 or 1. A byte (B) is 8 bits and is the standard unit for data storage. Internet speeds are typically measured in bits per second (Mbps), while file sizes are measured in bytes (MB). This means a 100 Mbps internet connection can download at about 12.5 MB/s (100 divided by 8). Watch for the capitalization: lowercase b for bits, uppercase B for bytes.
How much storage do I need?
For basic use (documents, email, web browsing): 128-256 GB is sufficient. For photos and moderate media: 512 GB to 1 TB. For video editing, gaming, or large media libraries: 2-4 TB. For professional video production or server storage: 4+ TB or RAID arrays. Cloud storage can supplement local storage for backup and syncing. Modern smartphones typically offer 128-512 GB, and most laptops ship with 256 GB to 1 TB SSDs.

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