Editorial pages
Paste the text: count characters (with and without spaces), words and standard editorial pages.
What a «cartella» is
In publishing and translation work isn't measured in pages, because a page changes with the typeface and the margins: it's measured in cartelle, blocks of characters. A character here means a character with spaces included, and the count takes line breaks in too. The unit comes from the typewriter: thirty lines of sixty characters make 1800 characters, and that is still the most used measure in Italy for translations.
The three sizes, and when they're used
1800 characters is the standard for translations in Italy. 2000 characters is the publishing cartella proper, the one publishers count a manuscript with. 1500 characters is used by some agencies and some journalism contracts. They're conventions, not rules: all three are here together precisely because the number to look at depends on who is paying you, and it's worth checking which of the three your contract names.
To give you a sense: with words of average length, counting the space that separates them, a 1800-character cartella is around 260-280 words. Counting by words is instead the standard in international translation, which is why it appears here next to the characters.
What is counted and what isn't
Every character of the text you pasted is counted, spaces and line breaks included, and it's the same thing the «characters (with spaces)» figure in word processors counts. What isn't here are the footnotes, headers and footers of a real file: only the text you paste arrives here, so if the document has them, those characters have to be added separately.
Nearby tools
For the full count of words, sentences and paragraphs there is Word counter, and to know how long it takes to read it or to say it out loud Reading time. If you're putting together a quote, the rate you actually need is worked out backwards by Freelance hourly rate.