Why does my 1 TB hard drive only show 931 GB on my computer?

Hard drive manufacturers use decimal definitions: 1 TB = 1,000,000,000,000 bytes. Your operating system uses binary definitions: 1 GiB = 1,073,741,824 bytes. When the OS divides the drive's actual byte count by the binary gigabyte value, it gets roughly 931 — not 1000. The drive isn't lying and neither is your computer; they're just using different definitions of 'gigabyte'.

What is the difference between GB and GiB?

GB (gigabyte) uses the decimal definition: 1 GB = 1,000,000,000 bytes. GiB (gibibyte) uses the binary definition: 1 GiB = 1,073,741,824 bytes. That's about a 7% difference — small per unit, but significant at scale. Storage manufacturers use GB; operating systems like Linux and older versions of Windows report in GiB but label it 'GB', which is the source of most confusion.

How many MB are in a GB?

In decimal: 1 GB = 1,000 MB. In binary: 1 GiB = 1,024 MiB. Most everyday contexts (mobile data plans, file sizes in apps, cloud storage) use the decimal definition — so 1 GB of mobile data means 1,000 MB. Technical and OS contexts often use binary, where 1 GiB = 1,024 MiB. The converter supports both, so you can be precise about which standard you need.

How do I convert bytes to megabytes?

To convert bytes to megabytes using the decimal standard, divide by 1,000,000. So 5,000,000 bytes = 5 MB. Using the binary standard, divide by 1,048,576 to get mebibytes (MiB). For most everyday purposes — checking a file size, estimating an upload — the decimal definition is what you want. Enter your byte count into the converter, select bytes as the source and MB as the target, and the result appears immediately.

Does this converter support bits as well as bytes?

Yes. The converter includes bits, kilobits, megabits, and gigabits alongside their byte equivalents. This is useful for network speeds — internet connections are measured in megabits per second (Mbps), while file sizes are in megabytes (MB). There are 8 bits in a byte, so a 100 Mbps connection can theoretically transfer 12.5 MB per second.

Data Size Converter — Bits, Bytes, KB, MB, GB & TB | Utilx

Source Value

Projected Output

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Hybrid Binary/Decimal Compute Ready

Demystifying Storage Calculations

You see a file size in megabytes but your upload limit is in kilobytes. Your hard drive is listed as 1 TB but Windows says it's 931 GB. Your internet plan is 200 Mbps but a 2 GB download still takes forever. Data size units are everywhere, they're inconsistent, and the binary-vs-decimal gap trips up even people who work with computers daily.

This data size converter lets you switch between bits, bytes, kilobytes, megabytes, gigabytes, terabytes — and their binary counterparts like MiB and GiB — in one place. Type your value, pick your units, get your answer. It runs 100% in your browser, no sign-up, no waiting, nothing sent to any server.

Quick Overview

Convert instantly — results calculate dynamically as you type.
Broad spectrum coverage — supports bits, bytes, KB, MB, GB, TB, and binary units like GiB, MiB.
Hybrid standards support — handles both manufacturers' base-1000 and systems' base-1024 definitions.
100% Private — computations execute locally. No storage metrics are sent to our servers.
Completely free — no billing, account creation, or limitations.

Operational Workflow

01

ENTER DATA SIZE

Type the storage or file size value. Whole numbers and decimals are both fully supported.

02

CHOOSE SOURCE UNIT

Select the starting unit, such as Bytes from file specs or Megabits from bandwidth.

03

SELECT TARGET UNIT

Pick your target output. Toggle between binary and decimal values instantly.

04

COPY RESULTS

The conversion updates instantly. Click to copy the precise scalar value.

When to Use This Tool

Developer API Thresholds

Verifying if payload structures fit under limits like 2 MiB? Convert binary MB to bytes for exact conditional logic checks.

Hardware Sizing Checks

Confirm why your 1 TB SSD shows 931 GB. Verify binary to decimal ratios to ensure nothing is missing from storage.

Bandwidth & Data Plan Caps

Internet plans measure speeds in bits (Mbps) but mobile plans cap in bytes (GB). Stop dividing by 8 in your head.

Key Features

Binary & Decimal Units

Supports base-1000 storage manufacturer standards and base-1024 operating system standards.

Bits & Bytes Conversions

Stop dividing network Mbps to file MB manually. The tool maps both systems side by side.

100% Client-Side

Runs locally using JavaScript. Your technical capacities and private file metrics never exit your machine.

No Restrictive Tiers

No billing modules, premium gates, or caps on conversion calculations. Fast and free.

Real-World Case

"Catching Silently Failing Upload Thresholds"

James, a junior backend developer, was integrating a third-party file upload API with a documented limit of "5 MiB per file." His frontend was reading file sizes in bytes from the browser's File API. He kept getting rejected uploads on files that looked fine. He opened the Utilx data size converter, switched to binary units, and converted 5 MiB — he got 5,242,880 bytes. His validation logic was comparing against 5,000,000 (the decimal megabyte). A one-minute conversion check caught a bug that had been failing silently for two days. He fixed the threshold and moved on.

Ecosystem Support

DIMENSIONAL SCALAR MASS CONVERSION ALL MODULES

FAQs

Hard drive manufacturers define 1 TB as exactly 1,000,000,000,000 bytes — the decimal standard. Your operating system, however, measures storage in binary: 1 GiB (gibibyte) = 1,073,741,824 bytes. When it divides the drive's total byte count by that binary figure, the result is about 931 — not 1,000. The drive is the full size it claims; the discrepancy is purely a difference in definitions. This converter lets you see both the decimal (TB) and binary (TiB) figures side by side.

Data & Docs

Data Size Converter