Short answer: paste your text above and read the counts live — words, characters with and without spaces, sentences, paragraphs, lines, plus reading and speaking time. A word is any run of non-space characters.
Where the limits actually are
University assignments often cap at 2,000 words, a tweet at 280 characters, and an SOP portal at a character count that includes spaces. Knowing which of the two character figures a form wants is the difference between an accepted upload and a rejected one, which is why both are shown here.
Reading time is a planning figure
200 words per minute is comfortable prose. A legal clause or a dense specification can be half that, and a rehearsal script read quickly can be faster than 130. Use the number to decide whether a section is too long, not to promise an audience a duration.