pH Calculator
Calculate pH, [H⁺], and [OH⁻] concentrations
Enter a pH value or [H⁺] concentration
pH Scale Reference
0
Battery Acid
1-2
Stomach Acid
3
Lemon Juice
4
Orange Juice
5
Black Coffee
6
Milk
7
Pure Water
8
Sea Water
9
Baking Soda
10
Ammonia
11
Soapy Water
12-13
Bleach
14
Drain Cleaner
Key Formulas
- pH = -log[H⁺]
- [H⁺] = 10^(-pH)
- pOH = -log[OH⁻]
- pH + pOH = 14
Important Notes
A solution with pH 7 is neutral. pH below 7 indicates acidity, while pH above 7 indicates alkalinity (basic). Each unit change in pH represents a 10-fold change in hydrogen ion concentration.
Understanding pH
pH (potential of Hydrogen) is a measure of how acidic or basic a water-based solution is. The pH scale ranges from 0 to 14, with 7 being neutral. Lower pH values indicate acidic solutions (more H⁺ ions), while higher pH values indicate basic solutions (more OH⁻ ions).
Common pH Values
1-2Stomach Acid
3Lemon Juice
5-6Black Coffee
7Pure Water
8-9Sea Water
10-11Baking Soda
12-13Bleach
14Drain Cleaner