You can find out the domain authority of your website by using the MOZ site explorer. The left most umber is the domain authority score of your website. There are several types of scores including poor (1-10), decent (11-20), fair (21-30), competitive (31-40), good (41-50), strong (51-60), excellent (61-70), outstanding (71-80), very outstanding (81-90) and rare (91-100). If your rating is poor, it means that your site is new and there are a lot of SEO work you need to do. Decent means your site is doing better than most new sites but you should do some SEO to improve it. Fair means your site is optimized in some ways for SEO but you still need to improve it. Competitive means you are getting closer to reaching the spot you want on the search result. Good means you are doing well in SEO and many popular e-commerce sites are in this score range. Strong means your SEO score is beginning to getting healthier. Sites that get a score of excellent and upwards are authority sites with many backlinks.