Page Authority and Domain Authority are Moz's comparative link-strength scores, not Google ranking factors, so there's no fixed number that counts as good everywhere. This guide gives realistic score ranges by site type, explains how the logarithmic scale distorts comparisons, covers how often Moz and Ahrefs refresh their indexes, and outlines what to actually do when a score drops.
There isn't a fixed number. Moz built Domain Authority and Page Authority as comparative metrics, meaning a score of 25 is only meaningful next to the scores of the sites you're actually trying to outrank. A local plumbing company in Ottawa competing against three other local plumbers might have a fantastic score at DA 18. A national retailer competing against established e-commerce brands might find DA 35 unimpressive. As a rough field guide: brand-new sites typically sit under 10, small established local businesses often land between 10 and 25, competitive mid-size sites run 25 to 45, and large publishers or enterprise brands frequently sit above 50. Wikipedia, government domains, and major platforms sit near the top of the 90s, which skews everyone's sense of what's normal. Judge your score against your actual competitive set, not against the internet as a whole.
These get conflated constantly, and it causes bad decisions. Domain Authority scores the entire domain's link profile, aggregating signals from every page that has earned backlinks. Page Authority scores a single URL, based on the links pointing directly at that page plus some inherited strength from the domain. A site can carry a high DA while a specific blog post sits with a low PA because nothing links to that post directly. This matters most when you're evaluating where a guest post or partnership link will actually land. A link placed on a high-DA site's low-PA archive page passes far less value than a link on a page with real inbound links of its own. Always check the PA of the exact page your link will sit on, not just the domain-level score, before assuming a placement is strong.
Moz built both scores on a 1-100 logarithmic scale, and this is the part most explanations skip. Equal point gains require exponentially more link equity as the score climbs. Going from DA 15 to DA 25 might take a modest, achievable link campaign. Going from DA 55 to DA 65 can require an order of magnitude more high-quality linking domains, because you're competing against sites that already have deep, established profiles. This is why a small business site can gain 10 points in a year through consistent outreach, while an already-strong site plateaus despite continued link building. It also means comparing point differences at different parts of the scale is misleading: a 5-point gap between two DA 20 sites is far less significant than a 5-point gap between two DA 70 sites. Treat the scale as tiers, not a linear ruler.
Moz has moved away from a strict fixed monthly refresh and now updates its link index and Domain Authority scores on a more continuous, rolling basis as its crawler processes new data, though the exact cadence can shift as Moz adjusts its systems. Ahrefs runs its own separate metric, Domain Rating, calculated from its own independent link index and updated on its own rolling schedule that does not align with Moz's. Because the two tools crawl different portions of the web and weight links differently, a site's Moz DA and Ahrefs DR will rarely match, and neither number is inherently more correct. If you need the current refresh cadence for either tool, check their official documentation directly rather than relying on older blog posts, since both companies have changed their update mechanics over time.
A falling DA rattles people, but it's rarely a sign of a Google penalty since the metric isn't a Google signal at all. The most common cause is losing referring domains: an old partner site removes your link, a directory shuts down, or an expired domain that once linked to you drops out of the index. The second common cause is a Moz model recalibration, where Moz adjusts how it weighs link signals across its entire index, causing many sites to shift up or down simultaneously regardless of anything they did. Before reacting, check whether competitors in your space also moved, which points to a model-wide change rather than something specific to you. If your score alone dropped, audit your referring domains for lost links and decide whether they're worth actively replacing.
DA is a useful first filter for link building, but it shouldn't be the only one. A reasonable floor for outreach targets is a DA that sits above your own, ideally by a meaningful margin, since links from stronger domains typically pass more value than links from weaker ones. But a site can carry a decent DA while being a link farm, an abandoned blog repurposed for paid placements, or a domain with real organic traffic in an unrelated niche. Before accepting or paying for a placement, check that the site has actual organic search traffic, topical relevance to your industry, and a link profile that looks earned rather than purchased in bulk. A DA 25 site with genuine relevant traffic in your niche is worth more than a DA 45 site stuffed with unrelated sponsored posts. Use DA to screen out obviously weak sites, then verify quality manually.
Local and regional Canadian businesses are often competing in smaller, less saturated markets than the national or US-based examples used in most SEO content, so the scores you should expect are naturally lower than what generic guides suggest. A Halifax accounting firm doesn't need to match the DA of a national bank's website to compete for local search visibility; it needs a DA that's competitive within its actual local result set, alongside strong on-page relevance and consistent citations. When benchmarking, pull the DA of the businesses currently ranking above you for your target terms in your city or province, not a generic industry average. Track your own score over time as a directional trend rather than a monthly obsession, and put more energy into earning genuinely relevant local links and citations than chasing a specific number.
There's no fixed good number; PA is comparative. A page competing for low-difficulty local terms might do fine with PA in the teens, while a page targeting competitive national keywords may need PA in the 30s or 40s relative to the pages currently ranking. Compare your page's PA against the pages actually ranking above you for the same query, not a general benchmark.
Most established small business sites land somewhere between 10 and 30, which is entirely normal. What matters more is how your DA compares to the businesses ranking above you locally. A DA of 20 can be perfectly competitive in a smaller city or niche where competitors haven't invested heavily in link building.
Moz has shifted from a fixed monthly schedule toward more continuous, rolling updates as its crawler processes new link data, though the exact cadence has changed over the years as Moz refines its systems. For the current, authoritative answer, check Moz's own documentation rather than older articles, since this detail is updated by Moz periodically.
The two most common causes are losing referring domains, such as a directory shutting down or a partner removing a link, or Moz recalibrating how it weighs signals across its entire index. Check whether competitors' scores moved too; if the whole industry shifted, it's a model update, not something you did wrong.
No. Domain Authority is a third-party metric built by Moz to estimate ranking potential based on link data, and Google has never confirmed using it or anything like it directly. It's a useful proxy for comparing link profiles and vetting link opportunities, but it doesn't feed into Google's actual algorithm.
Look for a DA higher than your own site as a baseline filter, then verify the site independently: check for real organic traffic, topical relevance to your industry, and a link profile that looks naturally earned rather than mass-purchased. A moderately-scored relevant site often passes more real value than a high-scored irrelevant one.