What is the pH reading of stomach acid? Chemistry Acids and Bases pH 1 Answer NickTheTurtle Apr 2, 2017 According to gastric acid on Wikipedia, its pH is around #1.5#-#3.5#. Answer link Related questions How do you determine pH from pKa? How do pH values of acids and bases differ? How do you calculate something on a pH scale? How do you calculate pH diprotic acid? How do you calculate pH from acid dissociation constant? How do you calculate pH of acid and base solution? Why is the pH scale 0-14? Is pH a measure of the hydrogen ion concentration? How does solubility affect pH? How does pH relate to pKa in a titration? See all questions in pH Impact of this question 1446 views around the world You can reuse this answer Creative Commons License