A supporting detail is a fact, example, reason, or description that helps explain or prove the main idea in a sentence or paragraph.

Quick Scoop

Think of the main idea as the point you want to make, and supporting details as the proof or extra information that makes that point clear. For example, if the main idea is “Exercise is good for your health,” supporting details could be “it strengthens your heart,” “it improves mood,” and “it helps you stay fit”.

Why it matters

Supporting details make writing easier to understand and more convincing because they give readers specific information instead of a vague claim. They can include facts, examples, explanations, descriptions, quotes, or anecdotes, depending on the kind of writing.

Easy example

  • Main idea: Dogs make great pets.
  • Supporting details: They are loyal, they can protect a home, and they often form strong bonds with people.

If you want, I can also give you a 1-sentence definition , a kid- friendly version , or practice examples.