Reading a KB upload limit
A 5 MB file is 5120 KB against a limit stated in kilobytes.
Use MB to KB
Converts megabytes to kilobytes in this tab, with nothing sent anywhere.
Runs entirely on your deviceThe conversion happens in this browser tab. Nothing you type is uploaded, logged or stored, which is worth knowing for anything you would not paste into a search box.
Five megabytes become 5,120 kilobytes under the 1,024-based convention. Web forms sometimes enforce a decimal five-million-byte ceiling, so a file shown as exactly 5 MB can still be rejected at the boundary.
Explore general converters
Find related browser-local tools for nearby tasks without starting another search.
Browse all general convertersAbout MB to KB
Sometimes a size given in megabytes needs to be in kilobytes - an upload field stated in KB, a comparison of small files, a quota. Converting megabytes to kilobytes expands the figure using 1024 KB per MB, the binary convention. So 5 MB is 5120 KB and a 0.5 MB image is 512 KB, the numbers an upload limit phrased in kilobytes wants. Some older upload forms and embedded systems still state their limit in kilobytes, so a file you think of in megabytes has to be expanded to check it fits. Image-optimisation targets are often written in kilobytes, so a photo you think of in megabytes is expanded to check it against a strict per-image budget. An application may enforce a byte limit even when its interface labels that limit in KB. Retain enough precision to distinguish a file just below an upload cap from one just above it; a rounded KB display may show both as the same size.
Using MB to KB
- Type a number of MB. You can paste a value with its unit; the tool reads the number.
- The exact factor is applied and the result is shown as KB, updating live as you type.
- Copy the answer, or switch to the reverse converter to go from KB back to MB.
Where mb to kb helps
Both directions
Need the opposite? The KB-to-MB converter is linked below and uses the exact inverse factor.
Leave room when enforcing a byte cap
The result for 2 MB is 2048 KB under this tool's 1024-based convention. A portal that defines 2 MB as 2,000,000 bytes has a smaller ceiling. Compare exact bytes where the destination publishes them, and avoid relying on a rounded file-manager label at the boundary. Renaming a file or converting the displayed unit does not change its size. Read the destination's documented byte ceiling before applying the conversion.
Before you use the result
- The result is rounded for readability, so a value converted and then converted back may differ in the last decimal place. The underlying factor is exact.
- Units in your input are ignored - only the number is read - so make sure the figure you type is really in MB.
Questions about MB to KB
How many KB in a MB?
1024 kilobytes make one megabyte in the binary convention this tool uses. The decimal convention used in some marketing counts 1000.
Is my data uploaded?
No. MB to KB does the arithmetic in this browser tab; the value is calculated on your device and is not sent to a server.
Related tools
KB to MB
Convert kb to mb instantly in your browser. Exact factor, both directions, nothing uploaded.
MB to GB
Convert mb to gb instantly in your browser. Exact factor, both directions, nothing uploaded.
GB to MB
Convert gb to mb instantly in your browser. Exact factor, both directions, nothing uploaded.