Sitemap Split Calculator
Sitemap file count from URLs and size under protocol caps.
What it does
Big sites outgrow one sitemap fast. Crawlers stop at 50000 URLs or 50 MB per file, and extra URLs past the cap simply never get listed. Splitting early keeps every page discoverable.
The tool above ceilings both limits. A site with 125000 URLs at 0.4 KB each needs 3 files by count against 1 by size, so count governs and an index ties the three together. Small pages split by count while media heavy maps split by size.
Both caps come from the shared protocol, not one search engine. Index files carry the same 50000 and 50 MB limits, so giant sites nest indexes carefully. Google echoes the rule in its sitemap docs.
Balance matters after the count. Even splits fetch faster and fail smaller than one giant file plus crumbs. Rebuild the index on each deploy so new files join the set.
How to use
- Enter total URL count.
- Enter average KB per URL entry.
- Read file count first.
- Read which limit governs.
- Add a sitemap index when files exceed one.
- Split URLs evenly across files.
Formula
- URLs
- URLs across the site.
- avg KB
- Average uncompressed KB per URL entry.
- 50000
- 50000 URLs per file cap.
- 50 MB
- 52428800 bytes (50 MB) per file cap.
The sitemaps protocol caps each file at 50000 URLs and 50 MB uncompressed, with the same caps on index files. Google repeats both limits and tells large sites to split across files under an index. The tool ceilings both sides and reports which limit governs.
Worked example
Example: 125000 URLs
Defaults: 125000 URLs at 0.4 KB average. These are also the default values, so the page opens on this answer.
- URLs: 125000.
- Average size: 0.4 KB per URL.
- Bytes: 125000 x 0.4 x 1024 = 51,200,000.
- By count: ceil(125000 / 50000) = 3.
- By size: ceil(51200000 / 52428800) = 1.
- Files: max(3, 1) = 3, so count governs.
- Tool shows 3 files with URL count governing and a sitemap index needed.
Reference table
| URLs | Count math | Files |
|---|---|---|
| 10000 | ceil(10000/50000) | 1 |
| 50000 | ceil(50000/50000) | 1 |
| 50001 | ceil(50001/50000) | 2 |
| 200000 | ceil(200000/50000) | 4 |
Limits
- Protocol planning only; crawl budget differs.
- Average KB is an estimate.
- Ignores per type sitemaps (news, video).
- Index nesting caps untested here.
Common mistakes
- Listing past 50000 in one file.
- Testing compressed size only.
- Skipping the index file.
- Uneven splits with crumb files.
- Forgetting new files in the index.
Try it yourself
Quick checks. Answers sit tucked under each question.
10000 URLs at 2 KB?
1 file with URL count governing and no index needed.
200000 URLs at 0.5 KB?
4 files with URL count governing and an index needed.
Questions
How are files found?
Take the larger of ceil URLs over 50000 and ceil bytes over 52428800. Here max(3, 1) = 3 files.
Protocol limits?
50000 URLs and 50 MB (52,428,800 bytes) uncompressed per file, same for index files.
More than one file?
List the files in a sitemap index so crawlers find them all.
Size side of the example?
Bytes: 125000 x 0.4 x 1024 = 51,200,000, which needs 1 file by size.
Gzip avoids splitting?
No. Compressed transfer helps fetching but limits test the uncompressed file.
Exactly 50000 URLs?
Yes: 50000 URLs at small size fits one file with no index.