Why do storage drives show less capacity in Windows?

Hard drive manufacturers sell capacity using decimal math (1 GB = 10^9 bytes), while Windows calculates file sizes using binary math (1 GiB = 2^30 bytes).

How many megabytes are in a gigabyte?

In standard decimal SI units, 1 GB = 1,000 MB. In binary IEC units, 1 GiB = 1,024 MiB.

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Data Storage Converter

Convert digital storage sizes between Bytes, KB, MB, GB, TB, and PB with Decimal (base 1000) and Binary (base 1024) support.

Data Storage Converter Interactive Workspace

Client-side calculations and instant parameter controls are initializing. All processing occurs securely in your browser.

How to Use the Data Storage Converter

1 Enter the data file or disk size.
2 Select the data unit (Bytes, KB, MB, GB, TB, PB).
3 Toggle between Decimal (1000 base) and Binary (1024 base) modes to compare drive manufacturer sizes with operating system reporting.

Mathematical Formula & Principle

Decimal: 1 GB = 1,000 MB (10^9 bytes) | Binary: 1 GiB = 1,024 MiB (2^30 bytes)

Calculations are performed with IEEE floating point mathematical precision directly in your device memory.

Worked Examples

Decimal Drive Capacity

Input: 1 Terabyte (TB)

Result: 1,000 Gigabytes (GB) = 1,000,000 Megabytes (MB)

Drive manufacturers use decimal powers of 1000.

Binary OS Formatted Space

Input: 1 Tebibyte (TiB)

Result: 1,024 Gibibytes (GiB) ≈ 931.32 GB Windows Display

Operating systems measure file storage in binary powers of 1024.

Frequently Asked Questions

Why do storage drives show less capacity in Windows?: Hard drive manufacturers sell capacity using decimal math (1 GB = 10^9 bytes), while Windows calculates file sizes using binary math (1 GiB = 2^30 bytes).
How many megabytes are in a gigabyte?: In standard decimal SI units, 1 GB = 1,000 MB. In binary IEC units, 1 GiB = 1,024 MiB.

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