File Size Converter

What is a file size converter?

Digital storage is counted in bytes, but there are two competing ways to scale them up. The decimal (SI) system uses powers of 1000: 1 kB = 1,000 bytes, 1 MB = 1,000,000 bytes. The binary (IEC) system uses powers of 1024: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes. Both are correct; they just measure with different rulers, and the gap grows with every step — about 2.4% at kilo, 7.4% at giga and 10% at tera.

This converter shows a size in every common unit at once — decimal, binary and bits — so you can compare what a hosting plan, an operating system and an ISP each mean. Pick a precision to control how many decimals are shown; each row has its own Copy button.

Connection speeds are quoted in bits per second, not bytes, so a 100 Mbps line moves at most 12.5 MB per second. The transfer-time estimate does that conversion for you and shows the ideal time at your speed plus a table of common speeds.

How to use the File Size Converter

1. Enter a number in Value and choose its unit — for example 4.7 and GB for a DVD image.
2. Read the conversions in the decimal, binary and bit tables. The unit you entered is highlighted.
3. Change Precision if you need more or fewer decimals, then click Copy on any row.
4. Optionally enter your connection speed to estimate how long the file takes to download or upload.

Example: a "1 TB" hard drive

Manufacturers sell storage in decimal terabytes, while Windows reports binary units with decimal-looking labels:

1 TB  = 1,000,000,000,000 bytes
      = 1,000,000,000,000 ÷ 1024³ = 931.32 GiB  (Windows shows "931 GB")
      = 1,000,000,000,000 ÷ 1024⁴ = 0.9095 TiB

WordPress and PHP upload limits

If a WordPress upload fails with "The uploaded file exceeds the upload_max_filesize directive", the limit is set by PHP, not WordPress. Two settings matter: upload_max_filesize (the largest single file) and post_max_size (the whole request, which must be at least as large). PHP shorthand like 64M means 64 × 1024 × 1024 bytes — binary mebibytes — so a 65 MB (decimal) video is about 62 MiB and fits, while a 70 MB file does not.

You can raise the limits in php.ini, a .user.ini file, or with php_value lines in .htaccess on Apache with mod_php (see the .htaccess Generator). Hosts often cap them regardless, so check Tools → Site Health → Info → Server for the effective values.

upload_max_filesize = 64M
post_max_size = 72M
memory_limit = 256M

Quick reference

• 1 KiB = 1,024 B; 1 MiB = 1,048,576 B; 1 GiB = 1,073,741,824 B.
• 1 GB = 0.9313 GiB; 1 GiB = 1.0737 GB.
• 1 byte = 8 bits, so 1 Gbps ≈ 125 MB/s before overhead.
• Lowercase b means bits and uppercase B means bytes: 10 Mb is 1.25 MB.