NaN% is the percentage you get when you try to convert the fraction sitemap.xml/undefined into a standard percentage. This result shows up because the denominator is not a real number, so the calculation can’t produce a meaningful value.
The fraction itself, sitemap.xml/undefined, is essentially undefined in mathematics. When you divide anything by an undefined or non‑existent value, the result isn’t a number you can work with, which is why the percentage comes out as NaN%. It’s a placeholder that signals the operation can’t be completed in the usual way.
In everyday terms, you can think of NaN% as “not a number” – a signal that the data you tried to convert doesn’t make sense in this context. It’s a useful reminder to check the inputs before doing any calculations.
