Hydrogen Ion Calculator
Calculate hydrogen ion concentration from pH and the dissociation it implies.
About Hydrogen Ion Calculator
Taking the antilog of the negative pH recovers hydrogen ion concentration. Even at pH 4.5 the concentration is only about 32 micromolar, yet that still corresponds to around 10¹⁹ protons per litre. The enormous particle count at tiny molar concentrations is why buffering works: small amounts of buffer can absorb large numbers of protons.
Formula
Hydrogen Ion
[H⁺] = 10^(−pH)
- antilog
- Inverting the logarithm recovers the concentration from pH
Worked example
With the default values below, Hydrogen Ion Calculator returns Hydrogen Ion Concentration of 0.000031622777. Change any input above and every figure here is recalculated in your browser.
Inputs used
- pHaccepts -2–16
- 4.5
- Solution volumeminimum 0 L
- 1 L
Results
- Hydrogen Ion Concentration
- 0.000031622777 mol/L
- Hydroxide Ion Concentration
- 0.00000000031623 mol/L
- Moles of Protons in the Volume
- 0.000031622777 mol
- Number of Protons
- 19,043,681,191,737,426,000
- pOH
- 9.5000
Step by step
- 1Values used
- 2Hydrogen Ion
- 3Hydrogen Ion Concentration= 0.000031622777 mol/L
- 4Hydroxide Ion Concentration= 0.00000000031623 mol/L
- 5Moles of Protons in the Volume= 0.000031622777 mol
- 6Number of Protons= 19,043,681,191,737,426,000
- 7pOH= 9.5000
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 14 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Hydrogen Ion calculated?
[H⁺] = 10^(−pH) Taking the antilog of the negative pH recovers hydrogen ion concentration. Even at pH 4.5 the concentration is only about 32 micromolar, yet that still corresponds to around 10¹⁹ protons per litre.
Why does Hydrogen Ion matter?
The enormous particle count at tiny molar concentrations is why buffering works: small amounts of buffer can absorb large numbers of protons.
What values do I need to enter?
This calculator takes 2 inputs: pH, Solution volume. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.