What is the M1V1 = M2V2 formula?

It states that concentration of titrant times its volume equals concentration of analyte times its volume: M1×V1 = M2×V2. This holds when the acid and base react in a 1:1 molar ratio (n1 = n2 = 1). For other ratios, use n1M1V1 = n2M2V2.

What units should I use?

Concentration must be in mol/L (molarity, M). Volume can be in any consistent unit (mL or L), as long as both volumes use the same unit — the units cancel in the equation.

Does this work for strong and weak acids?

Yes. The M1V1 = M2V2 equation applies to any acid-base pair at the equivalence point, whether strong or weak, because it only depends on stoichiometric moles, not degree of dissociation.

What are equivalents (n)?

Some acids or bases donate or accept more than one proton per molecule (e.g. H2SO4 has n=2). Setting n1 and n2 adjusts the equation to n1·M1·V1 = n2·M2·V2 for polyprotic systems.

How do I find the equivalence point volume?

Solve for V2: V2 = (n1·M1·V1) / (n2·M2). Enter the known concentration and volume of the titrant (side 1) and the concentration of the analyte (M2), then solve for V2.

Titration Calculator

Enter any three of concentration 1, volume 1, concentration 2, or volume 2 to find the missing value via M1V1 = M2V2.

Enter Known Values

Fill in three fields — leave the unknown blank (or select it below).

Solve for

Titrant (solution 1)

C1 — Concentration (mol/L)

V1 — Volume (mL)

Analyte (solution 2)

C2 — Concentration (mol/L)

V2 — Volume (mL)

Advanced — equivalents (polyprotic acids/bases)

n1 — equivalents of titrant

n2 — equivalents of analyte

Result

Enter values and click Calculate.

Quick Reference

General form n1 · M1 · V1 = n2 · M2 · V2

1:1 ratio M1V1 = M2V2

Solve C1 C1 = (n2·C2·V2) / (n1·V1)

Solve V1 V1 = (n2·C2·V2) / (n1·C1)

Solve C2 C2 = (n1·C1·V1) / (n2·V2)

Solve V2 V2 = (n1·C1·V1) / (n2·C2)

Summary

This titration calculator solves the M1V1 = M2V2 equation for any unknown — concentration or volume on either the titrant or analyte side. It supports polyprotic acids and bases by letting you set the number of equivalents (n) for each reactant. All arithmetic runs entirely in your browser; nothing is sent to a server.

How it works

Select which unknown you want to solve for (C1, V1, C2, or V2).
Enter the three known values with their units.
Click Calculate — the result appears instantly using M1V1 = M2V2.
Optionally enter the number of equivalents if the acid/base valences differ.
Use the Reset button to start a new calculation.

Use cases

Determine the concentration of an unknown acid or base after reaching the equivalence point.
Calculate how much titrant volume is needed to neutralize a given analyte.
Verify stoichiometry in acid-base neutralization lab experiments.
Check titration calculations before submitting chemistry coursework.
Convert between molarity and volume for any titrant-analyte pair.
Plan dilution steps before running a back-titration.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu