Kilobytes to Megabytes Calculator (KB ↔ MB)
Convert between kilobytes and megabytes — choose between the binary (IEC, 1 MB = 1 024 KB) and decimal (SI, 1 MB = 1 000 KB) standards. Also shows GB, TB and bytes.
Standard
Direction
KiB
IEC binary standard — 1 MiB = 1 024 KiB = 1 048 576 bytes
- 1
Megabytes per kilobyte
1 ÷ 1,024 = 0.0009771 MiB = 1,024 KiB (IEC binary). - 2
Convert to megabytes
1,024 ÷ 1,024 = 1
How does this calculator work?
Divide kilobytes by 1 024 (binary/IEC) or 1 000 (decimal/SI) to get megabytes. The binary standard is used by most operating systems; the decimal standard is used by hard-drive manufacturers and macOS. 1 024 KB = 1 MiB (binary) or 1.024 MB (decimal).
Formula
How this is calculated
There are two competing standards for data-size prefixes, which is why "1 MB" means different things in different contexts. The IEC binary standard (introduced in 1998) uses powers of 1 024: 1 kibibyte (KiB) = 1 024 bytes, 1 mebibyte (MiB) = 1 024 KiB = 1 048 576 bytes. The SI decimal standard uses powers of 1 000: 1 kilobyte (KB) = 1 000 bytes, 1 megabyte (MB) = 1 000 KB = 1 000 000 bytes.
Operating systems historically used the binary definition with the decimal label — for example Windows reports a 1 GB file as 1 073 741 824 bytes, while macOS switched to decimal in 2009 so the same file shows as about 1.07 GB. Storage manufacturers use decimal because it makes capacities appear larger. Network speeds are almost always decimal (megabits per second).
This calculator applies the chosen standard consistently across all scales. The factor per step (1 024 or 1 000) is applied repeatedly: KB → MB → GB → TB each multiplies or divides by the same factor.
Frequently asked questions
Both conventions are in common use. The IEC standard (used by most operating systems historically) defines 1 MiB = 1 024 KiB. The SI/decimal standard (used by storage manufacturers and macOS since 2009) defines 1 MB = 1 000 KB. Switch between them using the toggle above.
Windows uses the binary definition but labels it with MB/GB, while macOS switched to the decimal definition in OS X Snow Leopard (2009). So a 1-billion-byte file appears as about 954 MB in Windows and 1 GB in macOS.
Using the binary standard: 1 024 KB ÷ 1 024 = 1 MiB exactly. Using the decimal standard: 1 024 KB ÷ 1 000 = 1.024 MB.
Also known as
TG we-Calculate Editorial Team. (2026). Kilobytes to Megabytes Calculator (KB ↔ MB) [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/kilobytes-to-megabytes-calculator
TG we-Calculate Editorial Team. "Kilobytes to Megabytes Calculator (KB ↔ MB)." TG we-Calculate. 2026. https://we-calculate.com/calculator/kilobytes-to-megabytes-calculator.
TG we-Calculate Editorial Team, "Kilobytes to Megabytes Calculator (KB ↔ MB)," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/kilobytes-to-megabytes-calculator
@misc{wecalculate_kilobytes_to_megabytes_calculator, title = {Kilobytes to Megabytes Calculator (KB ↔ MB)}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/kilobytes-to-megabytes-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?