How is the AO3 purity score calculated?

The AO3 purity score formula

Purity score = (total questions − checked questions) ÷ total questions × 100.

Every question is weighted equally, and the final percentage is rounded to the nearest whole number.

Example with 217 questions

If you check 84 of the 217 statements, 133 remain unchecked. 133 ÷ 217 × 100 rounds to 61%, so your AO3 purity score is 61.

(217 - 84) / 217 * 100 = 61.29... -> 61

Why are all questions weighted equally?

The test is designed as a lightweight, shareable snapshot. Reading a rare pair, writing a long WIP and using a custom skin each count as one checked statement. That keeps the calculation transparent, even though people arrive at the same score in different ways.

Can I calculate a score from another version?

Yes. Enter any total question count and checked count in the AO3 purity score calculator. For the complete result, use the 217-question AO3 quiz.

Calculation checklist

• Count the total statements
• Count the statements you checked
• Treat the result as a playful snapshot, not a judgment