This converts a file size between bytes, kilobytes, megabytes, gigabytes, and terabytes, using the binary convention most operating systems use for displaying file sizes. It's a quick reference for translating a figure you've seen in one unit into whatever unit actually makes sense to you, whether that is checking an upload limit or comparing two storage plans.
How to use it
- Enter the file size you want to convert.
- Select the unit you're converting from.
- Select the unit you want the result in.
- Read the converted value.
- Change the original value anytime to see it update.
When it helps
- Checking whether a file fits an upload limit given in a different unit than the file shows.
- Converting a storage plan's advertised capacity into a more intuitive unit.
- Understanding how many megabytes a gigabyte sized download actually represents.
- Comparing file sizes listed in different units across sources.
- Estimating storage or bandwidth needs when planning a backup.
Good to know
- This uses 1024 as the factor between units, matching how most operating systems calculate file size.
- Some marketing materials use 1000 instead, which can make an advertised storage capacity look a little bigger than what your device actually reports.
- For very large numbers, double check you picked the right starting unit. Mixing up megabytes and gigabytes throws the answer off by a thousand times.
- When estimating how many photos fit on a device, convert the device's total storage and each average file size into the same unit before dividing, to avoid a mismatch.
- When budgeting cloud storage, calculate using the binary convention this tool uses, since that matches what most storage dashboards will actually report back to you.
Rounding and units
Storage makers use decimal units where a gigabyte is a billion bytes, while operating systems often show binary units, which is why a new drive appears smaller than its label.
Questions
Why does 1 GB sometimes look different here than on a spec sheet?
This uses the binary convention of 1024 bytes per kilobyte, matching how operating systems calculate file size, while some manufacturers advertise storage using 1000 instead, creating a small but real gap.
How many megabytes are in a gigabyte?
Using the binary convention here, exactly 1024.
What's the largest unit this supports?
Terabytes, which covers essentially every everyday file size and storage conversion.
Why do some file managers show a different size than this calculator?
Some systems round differently, or use the decimal 1000 based convention instead of the binary 1024 based one this calculator uses, creating a small gap for the same file.
Is a byte the smallest unit of storage?
It's the smallest this calculator handles and the smallest commonly discussed. Bits, which are smaller, mostly come up in networking speed contexts instead.
Is a kilobyte always 1024 bytes?
Under the binary convention this tool uses, yes. Under the alternative decimal convention some contexts use, a kilobyte is defined as 1000 bytes instead.