Paradise has 33 cantos and 4,758 lines, which comes to around 125 pages in an ordinary edition; counting by the words of the original gives about 123. The number varies with the edition, the page format, and the notes, but the order of magnitude is this. Each canto takes up, on average, between three and four pages.
The estimate starts from the roughly 32,000 words of the Italian original and takes into account that verse, with its line breaks, takes up more page than prose. The three canticles are of similar size: the Inferno and the Purgatory are each about 125 pages, so that the whole Comedy comes to around 370.
The site's reading schedule divides the work into two weeks, at about nine pages a day. The first week runs from cantos I to XVI, to Cacciaguida and ancient Florence, on the eve of the prophecy of exile, and the second, from cantos XVII to XXXIII, from the prophecy to the final vision. That is, on average, a little over two cantos a day.
Because it is poetry in terza rima, Paradise reads more slowly than the page count suggests, and it is the heaviest canticle to read: the number of names and references calls for pauses to look up what each one stands for. Whoever prefers a looser pace can read one canto a day and stretch the reading over more weeks.