Thank you! I would like to make homemade all purpose cleaner and the recipe calls for a 1 cup of vinegar with 5% acetic acid content mixed with a 1 cup of water. I only have vinegar with 9% acetic acid. Therefore I have to use 1.8 - 2 times less 9% acetic acid vinegar to get the same concentration as if using vinegar with 5% acetic acid content? FOLLOW UP ANSWER: For homemade cleaner, you don't have to be exact. You can use 1/2 - 3/4 cup of the 9% vinegar + 1 cup water (or any multiple thereof).