How to use the Chemistry Calculator
Start with Calculation mode, then enter the values shown for that mode. The result includes the selected quantity, Formula & steps, and Assumptions. The calculation runs in browser-side JavaScript, and the calculation code does not send entered values through a network request.
- Choose a mode from
Calculation mode, such as pH / pOH / [H+] / [OH-], Molarity, Dilution (C1V1 = C2V2), or Molar mass. - For pH, choose pH, pOH, [H+] (mol/L), or [OH-] (mol/L) from
Known value, then enterValue. - For a mode with
Solve for, choose the quantity to calculate and fill the other displayed fields. The fields change with the mode. - For a formula or reaction, enter
Chemical formula, or enter the coefficients and formulas required by the selected mode. SelectI have mass instead of molesorAdd a second reactant (to check for a limiting reagent)when those inputs apply. - Select
Calculateand reviewFormula & stepsandAssumptions. You can then useCopy result,Download result (.txt), orReset.
What pH, molarity, and dilution calculate
The pH mode assumes an aqueous solution at 25 °C and uses Kw = 1.0 x 10^-14. Enter one of pH, pOH, [H+], or [OH-], and the other three values are calculated. For example:
Known value: pH
Value: 4.5
Result: pOH 9.5, [H+] 3.162e-5 mol/LMolarity divides moles of solute by liters of solution. Select I have mass instead of moles to calculate moles from Mass (g) and Chemical formula. Dilution uses C1 x V1 = C2 x V2. Enter the same concentration unit for C1 and C2, and the same volume unit for V1 and V2; the mode keeps those units as entered.
What Chemical formula accepts
Enter element symbols with integer or decimal counts, nested parentheses or brackets such as Ca(OH)2 and Al2(SO4)3, or hydrates such as CuSO4.5H2O. The parser reports g/mol using conventional atomic weights. It rejects names, unknown element symbols, unsupported characters, unbalanced groups, and isotope-specific masses.
How stoichiometry, yield, and solution preparation use inputs
Stoichiometry requires the coefficients and formulas from a balanced equation. When you select Add a second reactant (to check for a limiting reagent), the calculator compares the possible product amount from each reactant and reports the smaller amount with its limiting reagent. It assumes the reaction reaches completion and does not balance or verify the equation.
Actual yield and Theoretical yield must use matching units. Solution preparation assumes a pure, dry solute dissolved to the stated final volume. Beer-Lambert law uses A = ε x c x l and requires your Molar absorptivity (L·mol-1·cm-1). Specific heat uses q = m x c x ΔT, with no phase change and constant specific heat capacity across the interval.
Three input patterns
- Enter pH 4.5 as
Valueto calculate the corresponding pOH and ion concentrations. - Enter a solute formula,
Target molarity (mol/L), andTarget volume, then chooseMass to weigh out. - Enter two reactant amounts, select
Add a second reactant (to check for a limiting reagent), and review the product comparison.
When another calculator matches the task
Use Science Calculators for Physics, Chemistry and More when the calculation moves beyond this page's chemistry modes. Choose the Molar Mass Calculator for formula parsing and an element breakdown. Choose the Dilution Calculator when you have any three of stock concentration, stock volume, target concentration, and final volume. The Beer-Lambert Law Calculator focuses on absorbance, concentration, path length, and absorptivity.
Frequently asked questions
How do I calculate pH with the Chemistry Calculator?
Choose pH / pOH / [H+] / [OH-] in Calculation mode, select one item from Known value, enter Value, and select Calculate. The other three values use the 25 °C assumption shown in the result.
Can I calculate molar mass from a chemical formula?
Yes. Choose Molar mass and enter Chemical formula. The parser accepts element symbols, counts, nested parentheses or brackets, and dot or asterisk hydrates, then reports the mass in g/mol.
How does the chemistry calculator find a limiting reagent?
Select Add a second reactant (to check for a limiting reagent). The calculator finds the possible product amount from each reactant and reports the smaller amount with its limiting reagent. Supply coefficients and formulas from a balanced equation.
Does the Chemistry Calculator balance equations or identify chemicals?
No. Enter valid formulas and balanced stoichiometry coefficients yourself. The calculator performs arithmetic on those values; it does not identify substances, look up equations, or provide laboratory safety guidance.