Entry: DR
Check domain rating by hand: the DR formula, worked
Entry: DR, a 0-100 integer computed from one input. This page defines it, shows the arithmetic and lists what it leaves out.
Definition
DR is round(100 x ln(R+1) / ln(2x10^7))
R is the number of distinct domains linking to the target in our index. The result is rounded to a whole number between 0 and 100. Nothing else enters the calculation. See the glossary for the vocabulary.
- Input: referring domains only
- Scale: logarithmic
- Our own metric, not Ahrefs DR or Moz DA
Example inputs and outputs
| Referring domains (R) | DR | Reading |
|---|---|---|
| 0 | 0 | No linking domain in the index |
| 1 | 4 | A single link already scores |
| 10 | 14 | Typical of a new blog |
| 100 | 27 | Small established site |
| 1,000 | 41 | Substantial; doubling to 2,000 adds only 4 points |
| 10,000 | 55 | Large publisher range |
| 1,000,000 | 82 | Top of the web |
| 20,000,000 | 100 | Ceiling of the scale |
Why the scale bends
A logarithm compresses large numbers. Going from 10 to 100 referring domains gains 13 points, whereas going from 100,000 to 1,000,000 gains about 14 points while needing 900,000 more domains.
This is the reason a low-DR site can climb quickly and a high-DR site seems stuck. The mathematics is behaving as designed. A site at DR 70 that gains 5,000 new domains may see its score move by one point or none.
Ahrefs publishes the idea behind its Domain Rating but not the exact computation, and Moz does the same for Domain Authority. Ours is open on purpose, which lets you check domain rating with a calculator.
Recomputing a score from a lookup
Read R
Take the referring-domain count from the free lookup on the home page. Say it is 340 in this example.
Add one and take the natural log
ln(341) is about 5.83. The plus one keeps a site with zero links at exactly zero.
Divide by ln(20,000,000)
That constant is about 16.81. So 5.83 divided by 16.81 is 0.347.
Multiply by 100 and round
The result is 34.7, which rounds to a DR of 35. The example is hypothetical, the method is exact.
Link quality, anchor text, follow attributes, topical relevance and traffic are not inputs. Ten links from one spammy network and ten from ten newspapers count equally if they come from distinct domains.
Before quoting a DR figure
- Write down the date of the lookup, since the index refreshes roughly monthly
- Say which metric it is: ours, Ahrefs DR, Moz DA or Semrush Authority Score
- Quote referring domains next to DR, so the reader can recompute
- Never present the number as a Google signal
- Compare sites only inside one tool
Short entries on common confusions
Can DR go down without losing links?
Yes, indirectly. Each monthly refresh rebuilds counts from the crawl, so a domain that was reachable last month and is not reached this month stops counting. The formula itself never changes.
Why twenty million as the ceiling?
It is the constant in the published formula. A site with twenty million referring domains scores 100, and anything beyond that is capped. No real site is expected to approach it.
Is a DR of 40 good?
It depends on the niche. In our scale 40 corresponds to roughly 800 referring domains, which is broad for a local business and modest for a national publication. Compare against rivals, not against a number.