What is domain authority?

The score is logarithmic. Moving from 20 to 30 takes far less work than moving from 70 to 80. That design keeps the top of the scale sparse, so only a few thousand domains worldwide sit above 90.

Moz calculates it from its own link index: how many domains link to you, and how strong those linking domains are. There is no on-page component. Your content quality, your page speed, and your keyword targeting do not enter the formula.

The number is comparative, not absolute. A DA of 35 means nothing on its own. It means something when the three sites you compete with for a query sit at 28, 31 and 60. That last one is the real answer to why you are on page two.

Ahrefs sells Domain Rating and Semrush sells Authority Score. Both do the same job with different link indexes, so the numbers do not convert between tools. A site at DA 40 might be DR 52. Pick one tool and stay with it.

I built RankPulse to watch DA and three other Moz numbers daily and email you when one moves. It is $9 a month for 3 domains. It cannot tell you why the number moved - no tool can - but you will know within 24 hours that it did.