Hair Product pH Checker

How the hair product pH chart works

pH measures how acidic or alkaline something is, from 0 to 14, with 7 as neutral. The scale is logarithmic: each whole step is ten times stronger than the one before, so a shampoo at pH 7 is about a hundred times more alkaline than hair at pH 5. The surface of hair and scalp sits around pH 4.5–5.5, and products near that range treat the cuticle most gently.

band            = the range your reading falls in (lower edge included)
compared w/ hair = 10 ^ |your pH − 5|  times more acidic or alkaline
fit             = your pH against the usual range for that product type

Where the band edges sit

The bands touch without gaps: each one includes its lower edge and stops just below the next. Anything under 3 counts as very acidic. Readings from 3 up to 3.5 are counted as acidic and hair-friendly, because a diluted rinse in that range is fine as a short rinse-out. Readings from 11 up to 12 stay in the strongly alkaline band, and the relaxer range starts at 12. These are rounded rules of thumb, not laboratory limits.

Why the product type matters

The same number means different things in different bottles. A pH of 9 is a warning sign in a conditioner but normal in a permanent color mixed with developer. So the checker also compares your reading with the usual range for that kind of product and explains what it means for that product. For relaxers, color and lighteners a pH reading never replaces a patch test, a strand test and the manufacturer’s instructions, and lightening or relaxing is best left to a licensed stylist.

How to test with pH strips

Buy strips that cover 0 to 14 and read in half steps. Dip a strip into a liquid product for a second or two. For thick creams, gels and conditioners, stir one part product into one part distilled water and test that. Compare the color with the chart on the pack in good light, within the time it gives. Strips are only accurate to about half a point, so a reading of 5 means somewhere around 4.5 to 5.5.

What pH cannot tell you

pH is only one property of a product. It says nothing about how harsh the cleansing agents are, how much slip a conditioner gives or whether an ingredient irritates your scalp. If you want an acidic rinse, the apple cider vinegar rinse calculator gives a safe dilution, and the ingredient checker reads the rest of the label. If a product burns or your scalp is sore or broken, rinse it off and see a board-certified dermatologist.