Data Storage Converter
Convert between data storage units using both decimal (SI) and binary (IEC) standards side by side.
Reviewed by the ToolNestr Editorial Team — July 2026
How data storage conversion works
Data storage units can be confusing because two competing standards exist. The SI (International System of Units) standard treats each step as a factor of 1000, following the metric system used for most physical measurements. The IEC (International Electrotechnical Commission) standard uses factors of 1024, reflecting the binary nature of computer memory addressing. This calculator converts between both systems simultaneously so you never have to wonder which number is correct.
Internally, all values are converted to bits (the smallest unit) using the appropriate multiplier chain for the selected unit. For SI units, the chain is: 1 KB = 1000 B, 1 MB = 1000 KB, and so on. For IEC units: 1 KiB = 1024 B, 1 MiB = 1024 KiB, etc. Once the value is in bits, it is divided by each target unit's factor to produce the full conversion table you see in the results panel.
The formula explained
Worked example
Convert 1 GB to all units.
Hard Drive Shopping
Manufacturers advertise in SI (1 TB = 1000 GB), but your OS reports in IEC (931 GiB). See the real capacity before you buy.
Video Storage Planning
A 4K movie is roughly 15–25 GB. Quickly convert to MB or TB to plan how many films fit on your NAS or portable drive.
Cloud Storage Tiers
Compare 100 GB vs 200 GB vs 2 TB cloud plans. Convert between units to understand exactly how much space you are paying for.
Bandwidth Allocation
ISPs advertise in bits per second. Convert to bytes per second to understand real-world download speeds for your data cap.
How to use the data storage converter
Enter a value
Type the numeric value you want to convert. Decimals are supported for precision.
Select the unit
Choose the unit of your input value from the dropdown, including both SI and IEC options.
Read both scales
View the converted result in all SI and IEC units simultaneously. Compare decimal vs binary at a glance.
Tips for working with storage units
Know your context
Hard drive, SSD, and USB stick manufacturers always use SI units. RAM sizes always use IEC (binary) units. Network speeds use bits per second.
The 7% rule of thumb
An SI gigabyte is about 7% larger than an IEC gibibyte. Multiply GB by 0.9313 to get GiB, or GiB by 1.074 to get GB for quick mental conversion.
Watch for lowercase vs uppercase
Capital B means bytes, lowercase b means bits. MB and Mb are very different — 1 MB = 8 Mb. Always check the casing when reading specs.
Use the right tool for the job
For most everyday conversions like file sizes and disk space, this converter gives you both standards. For network speed conversions, use the data transfer rate converter.
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Frequently asked questions
Why are there two different values for KB/MB/GB?
SI uses powers of 1000 (decimal) while IEC uses powers of 1024 (binary). Hard drive manufacturers use SI, while operating systems typically report in IEC.
What is the difference between a bit and a byte?
A byte is 8 bits. Network speeds are usually in bits per second, while file sizes are in bytes.
How many MB are in a GB?
1 GB = 1000 MB (SI) or 1024 MiB (IEC). The answer depends on which standard you are using.
Which standard should I use?
Use SI for hard drive and network marketing specs. Use IEC (binary) for RAM, OS file sizes, and most technical contexts.
What is a pebibyte?
A pebibyte (PiB) is the binary equivalent of a petabyte (PB). 1 PiB = 1024 TiB = 1,125,899,906,842,624 bytes.