pH ranges from 0 to 14, and this number indicates a substance’s ratio of acidity and alkalinity, with 0 the most acidic, 14 the most alkaline, and 7 neutral. In its healthiest state, your skin is slightly acidic, usually 5.5. If your skin is too acidic, it can be irritated, prone to breakouts, and very oily. If your skin is too alkaline, it can look dull, feel extremely dry, and become flaky. Balance is key here.