The sitemap size calculator estimates how many XML sitemap files your website needs based on Google's limits: a maximum of 50,000 URLs per file and 50 MB uncompressed per file. Enter your total URL count and average URL length to instantly see file counts, sizes, and whether you need a sitemap index file.
Configuration
How many URLs you want to include in your sitemap
Typical full URL including https://domain.com/path/
Include optional fields
~80% size reduction typical for XML sitemaps
Detailed Breakdown
| Bytes per URL entry | — |
| URLs per sitemap file | — |
| Bytes per sitemap file | — |
| Total sitemap size | — |
| Est. generation time | — |
| Limiting factor | — |
How to Use the Sitemap Size Calculator
An XML sitemap is one of the most important SEO files on your website. It tells search engines which URLs to crawl, when they were last updated, and how frequently they change. But sitemaps have hard limits: no more than 50,000 URLs and no more than 50 MB per file (uncompressed). This sitemap size calculator tells you exactly how many files you will need and whether a sitemap index file is required.
Step 1: Enter Your Total URL Count
Type the total number of URLs you want to include in your sitemap. This should be the number of unique, canonical, indexable pages on your website — excluding redirects, noindex pages, paginated duplicates, and other non-indexable URLs. Including junk URLs wastes crawl budget and dilutes the sitemap's signal value.
Step 2: Set the Average URL Length
Enter the typical character length of your full URLs including the protocol and domain. A simple blog URL like https://example.com/blog/my-post/ is about 38 characters. An e-commerce URL with category paths might be 80–120 characters. The length affects per-entry byte size and therefore total file size.
Step 3: Select Optional Fields
Choose which optional XML fields to include: lastmod, changefreq, and priority. Each adds bytes per URL entry. Note that Google largely ignores changefreq and priority in practice, but does use accurate lastmod values to prioritize re-crawls of recently updated content.
Step 4: Toggle Gzip Compression
Gzip compression reduces XML sitemap file sizes by approximately 70–90%. Enable this if your web server supports serving gzip-encoded files (most modern servers do automatically). Google and Bing accept gzip-compressed sitemaps. The calculator shows both the uncompressed and estimated compressed sizes so you can compare both scenarios.
Step 5: Review the Results
The calculator shows how many sitemap files are needed, whether a sitemap index file is required, the total size in both compressed and uncompressed form, and an estimated generation time. If the "Limiting factor" is URLs rather than size, you are hitting the 50,000 URL cap. If it is size, your average URL length is pushing you over the 50 MB limit before reaching 50,000 URLs. The crawl budget note at the bottom gives context for whether your URL count warrants concern about Google's crawl allocation.
FAQ
Is this sitemap size calculator free?
Yes, completely free with no usage limits. All calculations happen instantly in your browser — no data is sent to any server, no signup required.
What are the XML sitemap size limits set by Google and Bing?
A single XML sitemap file can contain a maximum of 50,000 URLs and must not exceed 50 MB uncompressed. If your site exceeds either limit, you need multiple sitemap files plus a sitemap index file that lists all individual sitemaps. Most major search engines including Google and Bing enforce these same limits.
When do I need a sitemap index file?
You need a sitemap index file when your URLs span more than one sitemap file — that is, when you have more than 50,000 URLs or when a single sitemap would exceed 50 MB. The sitemap index is an XML file that lists the URLs of all your individual sitemap files. Search engines follow the index to discover all your sitemaps.
What does gzip compression do to XML sitemap size?
Gzip compression typically reduces XML sitemap file size by 70–90%. A 10 MB uncompressed sitemap often compresses to under 1.5 MB. Most web servers can serve .gz files automatically. Google and Bing accept gzip-compressed sitemaps as long as they are served with the correct Content-Encoding: gzip header. Compression allows you to serve sitemaps faster and use less bandwidth.
How long does it take for Google to crawl a large sitemap?
Google does not crawl a sitemap file itself — it reads the sitemap and then schedules crawls for the URLs listed within it. Larger sitemaps do not directly slow down crawling, but sites with millions of URLs may find that Google allocates limited crawl budget. This calculator provides rough generation time estimates based on typical sitemap generator throughput of 1,000–5,000 URLs per second.
Should I include lastmod, changefreq, and priority in my sitemap?
Google has stated that it largely ignores changefreq and priority values in sitemaps, treating them as unreliable signals. However, lastmod (last modification date) is used by Google to decide whether to re-crawl a URL. Including accurate lastmod values can help Google discover content updates faster. If your CMS cannot provide accurate lastmod dates, it is better to omit the field than to provide inaccurate values.
What is crawl budget and how does sitemap size affect it?
Crawl budget is the number of pages Googlebot will crawl on your site within a given timeframe. Large sitemaps with hundreds of thousands of URLs do not directly reduce crawl budget, but they do mean more URLs competing for the same budget. Keeping sitemaps focused on canonical, indexable URLs (excluding redirects, noindex pages, and duplicate content) helps Google spend its crawl budget on your most valuable pages.
What is the overhead XML added per sitemap file?
Each XML sitemap file has a fixed header and footer overhead of approximately 100–200 bytes for the XML declaration and urlset wrapper tags. Per-URL overhead includes the url, loc, lastmod, changefreq, and priority elements, which add roughly 100–400 bytes beyond the URL itself depending on which optional fields you include.