How to add blogspot blog site map to Google webmaster tool using feeds

Login to Google webmaster  tool and go to Sitemaps -> Overview. Enter the path of your Sitemap file, relative to your blog's root, in the given text field and click Submit Sitemap. For Blogger blogs, the default RSS feed can be used as the Sitemap. Given below is relative path of such a feed.

feeds/posts/default?max-items=200&start-index=1

http://[your blog name].blogspot.com/feeds/posts/default is the default RSS feed for your blog. Since the RSS feed is an XML file, that can work as a Sitemap. The two parameters we provided in the above line instruct Google webmaster  tool to take 200 posts starting from the first post, as the content of this Sitemap. Later, if you want to add the second 200 posts, all you have to do is to add another Sitemap which looks like:

feeds/posts/default?max-results=200&start-index=201

It is not a must to submit 200 posts at a time. It can be any number as long as the Sitemap does not exceed the limit of 50,000 URLs or 10MB in size.

Once submitted Google webmaster  tool will automatically determine the Sitemap type and then start processing it.