Processed client-side in your browser — files never leave your device.
Free, with no signup, account, or usage limits.
Works on any modern browser, including mobile.
About this tool
File Size Calculator helps you calculate file sizes in different units. Processing runs locally in your browser — your input is not uploaded to ThothBox.
How to use
Open File Size Calculator and add your file (upload or drag and drop).
Set the options that match your goal.
Run the action — processing happens in your browser.
Download or copy the result when it is ready.
FAQ
What does File Size Calculator do?
Calculate file sizes in different units.
Is File Size Calculator private?
Yes for typical use: input is processed in your browser and is not uploaded to ThothBox.
Is File Size Calculator free?
Yes. It is free to use with no signup required.
Are there file size limits for File Size Calculator?
Practical limits depend on your device memory and browser, not a ThothBox server quota.
How do I use File Size Calculator?
Open the File Size Calculator tool, then open File Size Calculator and add your file (upload or drag and drop).