File Size Calculator – Complete Guide To Bytes, KB, MB, GB & TB
The File Size Calculator on MyTimeCalculator helps you convert between common storage units such as bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes. It is useful whenever you want to compare files, estimate backup sizes or understand how much space photos, videos and archives really take.
Modern devices and cloud services expose file sizes in many different formats. One program might say a video is “1.4 GB”, another shows “1,536 MB”, and a backup tool might report “1,610,612,736 bytes”. This calculator unifies these views and makes it easy to translate from one unit to another.
1. Binary File Size Multiples
The calculator uses binary multiples based on powers of 1024. In this system, each unit is exactly 1024 times larger than the previous one:
- 1 KB = 1024 bytes.
- 1 MB = 1024 KB = 1024² bytes.
- 1 GB = 1024 MB = 1024³ bytes.
- 1 TB = 1024 GB = 1024⁴ bytes.
- 1 PB = 1024 TB = 1024⁵ bytes.
These powers of two align naturally with how memory and storage are addressed in digital hardware, which is why most operating systems and technical tools follow this convention when showing file sizes.
2. How The File Size Calculator Works
When you enter a value and choose a unit in the Convert Size tab, the calculator first converts everything to a base number of bytes. It then divides or multiplies by the appropriate powers of 1024 to generate KB, MB, GB, TB and PB. Finally, it picks a “best” human-readable unit where the numeric value is between about 1 and 1000.
For example, if you enter 2048 KB, the calculator converts 2048 KB to bytes, then back to other units. In this case 2048 KB equals 2 MB, about 0.001953 GB and so on. The Best Human-Readable Size card would typically show something like “2 MB”.
3. Human-Readable Breakdown Of Large Sizes
Large numbers of bytes can be hard to interpret at a glance. The Breakdown Table tab addresses this problem by decomposing the last converted value into a hierarchical mix of TB, GB, MB, KB and bytes. The idea is similar to expressing time as hours, minutes and seconds instead of raw seconds.
For instance, a backup of 1,234,567,890 bytes might be broken down into:
- 1 GB
- 148 MB
- 952 KB
- 722 bytes
This makes it much easier to reason about storage requirements and to check whether a disk or cloud plan has enough free capacity for your data.
4. Binary vs Decimal Units (KB vs kB)
Technically there is a distinction between binary and decimal units:
- Binary: 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, etc.
- Decimal: 1 kB = 1000 bytes, 1 MB = 1000 kB, 1 GB = 1000 MB, etc.
Standards bodies introduced separate symbols (KiB, MiB, GiB) for binary units, but in everyday usage “KB” and “MB” are still often used for binary values. This calculator follows the binary convention because it matches what you see in file explorers and most backup tools.
5. Common Real-World File Sizes
Typical file sizes fall into ranges that you can quickly estimate using the conversion rules:
- Plain text files and small documents: a few KB to a few MB.
- High-resolution photos: a few MB to tens of MB per image.
- HD videos: hundreds of MB to several GB per file depending on length and compression.
- Software installers and games: from hundreds of MB up to tens of GB.
- Full PC backups: from hundreds of GB to multiple TB, depending on usage.
By converting everything to a common unit like GB or TB, you can plan how many files fit on an SSD, HDD or cloud storage plan and avoid unexpected space issues.
6. Practical Steps For Using The File Size Calculator
- Note the file size from your operating system, application or device in whatever unit is shown.
- Enter the numeric value into the File Size Calculator and choose the matching unit.
- Click convert to see the size expressed in all other units from bytes to petabytes.
- Use the Best Human-Readable Size to communicate the result in a compact, user-friendly way.
- Switch to the Breakdown Table tab to see a detailed decomposition into TB, GB, MB, KB and bytes for large sizes.
- Use the Formula Guide tab as a quick reference to remember how many bytes are in each storage unit.
7. Limitations And Rounding
The calculator rounds results to a fixed number of decimal places for readability. Internally it still works with full floating-point values, but very large sizes may accumulate tiny rounding differences across conversions. These differences are usually far below one byte at the scales where KB, MB and GB are used.
Also note that storage device manufacturers often quote capacity in decimal units (for example, 1 TB = 10¹² bytes). When your operating system reports the same drive in binary units, the numeric value can appear lower. This is a labelling difference rather than missing space.
File Size Calculator FAQs
Frequently Asked Questions
Answers to common questions about converting file sizes between bytes, KB, MB, GB and TB using this calculator.
To convert bytes to kilobytes, divide by 1024. To get megabytes, divide by 1024 twice, and to get gigabytes divide by 1024 three times. For example, 1,048,576 bytes ÷ 1024 ÷ 1024 = 1 MB. The File Size Calculator automates these steps and shows all units at once so you do not have to chain the divisions by hand.
Many drive manufacturers use decimal units, where 1 TB is defined as 1,000,000,000,000 bytes. Operating systems usually interpret TB as a binary unit, where 1 TB = 1024⁴ bytes, which is larger. The same fixed number of bytes therefore appears as slightly less than 1 TB in the binary sense. No usable space is lost; the difference comes from the unit convention.
KiB, MiB and GiB are explicit binary units: 1 KiB = 1024 bytes, 1 MiB = 1024² bytes and so on. KB, MB and GB are sometimes used for decimal units (powers of 1000) and sometimes for binary units (powers of 1024). This calculator follows the binary convention, which matches most file system displays and technical documentation for storage and memory sizes.
Yes. You can total the sizes of representative files or folders in your preferred unit, convert to a higher-level unit such as GB or TB and then compare with your available disk or cloud storage capacity. The human-readable breakdown and multi-unit output help ensure that all of your estimates use consistent units and avoid accidental under- or overestimation of space needs.
When the input value is an exact multiple of a unit boundary, conversions can produce whole numbers in certain units, such as exactly 1 MB or 2 GB. For other units, the value might not divide evenly by powers of 1024, so the result requires decimal places. The calculator fixes the number of displayed decimals for readability while still reflecting these fractional relationships accurately.