Reference
Megabytes to kilobytes, both ways: multiply by 1,000 or by 1,024.
Runs in your browser. Nothing you type is uploaded.
Quick answer
MB to KB converter: 1 MB = 1,000 KB (decimal) and 1 MiB = 1,024 KiB (binary). To convert MB to KB, multiply by 1,000. To convert MiB to KiB, multiply by 1,024. Example: 2.5 MB = 2,500 KB, while 2.5 MiB = 2,560 KiB.
How many KB in a MB?
There are 1,000 KB in 1 MB in decimal units, and 1,024 KiB in 1 MiB in binary units. The table below lists both for common sizes.
How to convert MB to KB
KB = MB × 1,000. KiB = MiB × 1,024. This page multiplies the number you type both ways and labels each result. It does not turn megabytes into bytes first. If you start from a byte count, use the byte to MB converter. To go the other direction, use the KB to MB converter.
- 0.5 MB is 500 KB decimal, or 512 KiB if the 0.5 were MiB.
- 2.5 MB is 2,500 KB decimal and 2,560 KiB binary.
- 10 MB is 10,000 KB decimal and 10,240 KiB binary.
- Fast estimate: move the decimal point three places right. 3.2 MB is about 3,200 KB.
MB to KB conversion table
| Megabytes | KB (× 1,000) | KiB (× 1,024) |
|---|---|---|
| 0.1 | 100 KB | 102.4 KiB |
| 0.25 | 250 KB | 256 KiB |
| 0.5 | 500 KB | 512 KiB |
| 1 | 1,000 KB | 1,024 KiB |
| 1.5 | 1,500 KB | 1,536 KiB |
| 2 | 2,000 KB | 2,048 KiB |
| 2.5 | 2,500 KB | 2,560 KiB |
| 3 | 3,000 KB | 3,072 KiB |
| 4 | 4,000 KB | 4,096 KiB |
| 5 | 5,000 KB | 5,120 KiB |
| 8 | 8,000 KB | 8,192 KiB |
| 10 | 10,000 KB | 10,240 KiB |
| 16 | 16,000 KB | 16,384 KiB |
| 20 | 20,000 KB | 20,480 KiB |
| 25 | 25,000 KB | 25,600 KiB |
| 50 | 50,000 KB | 51,200 KiB |
| 64 | 64,000 KB | 65,536 KiB |
| 100 | 100,000 KB | 102,400 KiB |
| 128 | 128,000 KB | 131,072 KiB |
| 250 | 250,000 KB | 256,000 KiB |
| 256 | 256,000 KB | 262,144 KiB |
| 500 | 500,000 KB | 512,000 KiB |
| 1,000 | 1,000,000 KB | 1,024,000 KiB |
Values marked ≈ are rounded to six decimal places. Unmarked values are exact.
KB to MB
| Kilobytes | MB (÷ 1,000) | MiB (÷ 1,024) |
|---|---|---|
| 100 | 0.1 MB | ≈ 0.097656 MiB |
| 250 | 0.25 MB | ≈ 0.244141 MiB |
| 500 | 0.5 MB | ≈ 0.488281 MiB |
| 512 | 0.512 MB | 0.5 MiB |
| 1,000 | 1 MB | ≈ 0.976563 MiB |
| 1,024 | 1.024 MB | 1 MiB |
| 2,048 | 2.048 MB | 2 MiB |
| 5,000 | 5 MB | ≈ 4.882813 MiB |
| 10,000 | 10 MB | 9.765625 MiB |
MB to KB for photos, PDFs and signatures
Upload forms usually set a limit in KB while phones and scanners report MB. A 2 MB photo is 2,000 KB, so it is over a 200 KB limit by a factor of ten. To get a photo, a signature or a scan under a KB limit, use photo resize in KB, compress image to 20 KB or compress PDF to 200 KB. They run in your browser and do not upload the file.
Is MB bigger than KB?
Yes. A megabyte is 1,000 times larger than a kilobyte in decimal units, and a mebibyte is 1,024 times larger than a kibibyte in binary units. That is why the same file has a bigger number in KB than in MB.
Why the 1,024 shows up
A kibibyte is 2^10 = 1,024 bytes and a kilobyte is 1,000 bytes. A mebibyte is 1,024 KiB, so 1 MiB is 1,024 KiB, which software often prints as 1,024 KB. The decimal megabyte is 1,000 KB. The two answers differ by 2.4% at this step.
That small gap compounds as the unit grows. The next step up, MB to GB, shows the same pair one prefix higher. For a figure that starts in bytes, the file size formatter writes it in every unit at once.
Frequently asked questions
How many KB are in 1 MB?
There are 1,000 KB in 1 MB (decimal). There are 1,024 KiB in 1 MiB (binary), which Windows labels as 1,024 KB.
How do I convert MB to KB?
Multiply the megabytes by 1,000 for decimal kilobytes, or by 1,024 for binary kibibytes. 5 MB = 5,000 KB, while 5 MiB = 5,120 KiB.
Is 1 MB 1,000 KB or 1,024 KB?
The standard decimal megabyte is 1,000 KB. The binary mebibyte is 1,024 KiB, and plenty of software still calls that unit MB.
How many KB is 2 MB?
2 MB = 2,000 KB in decimal. 2 MiB = 2,048 KiB in binary.
How many KB is 0.5 MB?
0.5 MB = 500 KB in decimal, or 512 KiB if the half megabyte is binary.
How many KB is 10 MB?
10 MB = 10,000 KB in decimal and 10 MiB = 10,240 KiB in binary.
How many bytes are in 1 KB?
1 KB = 1,000 bytes. 1 KiB = 1,024 bytes.
Does this converter upload my numbers?
No. The conversion runs in your browser with exact integer arithmetic, so nothing you type leaves the page.
Is MB bigger than KB?
Yes. 1 MB = 1,000 KB in decimal units, and 1 MiB = 1,024 KiB in binary units.
How many KB is 1 MB for a PDF?
1 MB is 1,000 KB for a PDF too, because the unit does not depend on the file type. A 1 MB PDF is 1,000 KB. To shrink a PDF below a KB limit, use compress PDF to 200 KB or compress PDF to 100 KB.
How do I reduce a photo from MB to KB?
Converting units does not change a file. To make a photo smaller, reduce its pixel size, its JPEG quality, or both. The photo resize in KB tool does this in your browser until the file is under the KB size you choose.