Data Storage Converter
Convert between bytes, KB, MB, GB, TB and the binary units KiB, MiB, GiB using 1,024 steps. Explains why a 1 TB drive shows about 931 GB.
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Result
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Educational estimates · not financial advice · free, no signup
Formula / how it works
This tool uses binary steps: 1 KB = 1,024 B, 1 MB = 1,024 KB, 1 GB = 1,024 MB, 1 TB = 1,024 GB. KiB, MiB, GiB follow the same 1,024 steps. Drive makers use decimal units: 1 TB = 10¹² bytes ≈ 931.3 GiB.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
Storage units cause confusion because two conventions coexist. Operating systems and many technical documents count in powers of 1,024, while storage manufacturers and networking usually count in powers of 1,000. A drive sold as 1 terabyte holds 1,000,000,000,000 bytes, which an operating system using binary units reports as about 931 gigabytes. This converter changes values among bytes, KB, MB, GB, TB and the unambiguous binary units KiB, MiB and GiB, using steps of 1,024. Use it for file sizes, memory, backups and any calculation where you need to match what a system reports.
When to use / who it helps
- You want to know how many MB are in a GB in the binary sense.
- You are comparing advertised and reported drive capacity.
- You are estimating whether files fit on a device.
- You are working with memory sizes, which are binary.
- You are converting units for documentation or scripts.
How to use
Steps
- Enter the value.
- Choose the From unit.
- Choose the To unit.
- Read the result.
- Use KiB, MiB and GiB when you want unambiguous binary meaning.
- For decimal (manufacturer) units, multiply by powers of 1,000 manually.
How to interpret results
- 1,024 MB per GB is the binary convention used by many operating systems.
- KiB, MiB and GiB were introduced to remove ambiguity; KB, MB and GB may mean either.
- A 500 GB decimal drive is about 465.7 GiB.
- The difference grows with size, about 7% at GB and about 10% at TB.
- Network speeds are typically decimal, so download time estimates differ.
Common mistakes & gotchas
- Assuming a drive is faulty because it shows less capacity than advertised.
- Mixing bits and bytes; a byte is 8 bits.
- Using 1,000 where a system reports 1,024-based units.
- Forgetting formatting overhead and system files.
- Comparing decimal and binary units in one calculation.
Worked example
Worked example — 1 GB in MB, and a 1 TB drive in GiB
- This tool: 1 GB = 1,024 MB.
- A 1 TB drive has 1 × 10¹² bytes.
- Divide by 1,024³ (1,073,741,824) to get GiB: 931.32 GiB.
- A 500 GB decimal drive: 5 × 10¹¹ ÷ 1,073,741,824 ≈ 465.66 GiB.
Result: 1 GB is 1,024 MB in binary, and a 1 TB drive is about 931 GiB.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
This tool uses binary steps: 1 KB = 1,024 B, 1 MB = 1,024 KB, 1 GB = 1,024 MB, 1 TB = 1,024 GB. KiB, MiB, GiB follow the same 1,024 steps. Drive makers use decimal units: 1 TB = 10¹² bytes ≈ 931.3 GiB.
Frequently asked questions
How many MB are in a GB?
1,024 in binary units, 1,000 in decimal units.
What is the difference between GB and GiB?
GB can mean 10⁹ bytes or 2³⁰ bytes depending on context; GiB always means 2³⁰ bytes.
Why does my 1 TB drive show 931 GB?
The maker uses decimal terabytes, and the operating system reports binary units.
What is a byte?
Eight bits.
Does this tool use decimal or binary?
Binary, steps of 1,024.
How do I convert Mbps to MB/s?
Divide by 8, since there are 8 bits in a byte.