*A typical paragraph is roughly 5-7 sentences, or 150 words. BUT, that is only a guideline. Some paragraphs are longer than others. Use the following guidelines when making decisions about paragraph length and when to start a new one!
Start a new paragraph...
When you begin a new idea or point. New ideas should always start a new paragraph. If you have an extended idea that spans multiple paragraphs, each new point within that idea should have its own paragraph.
When your readers need a pause. Breaks between paragraphs are a short "break" for your readers—adding these in will help your writing be more readable. You would create a break if the paragraph becomes too long or the ideas are taxing on the brain!
To contrast information or ideas. Separate paragraphs can serve to contrast sides in a debate, different points in an argument, or any other difference.
When you are ending your introduction or starting your conclusion. Your introductory and concluding material should always be in a new paragraph.