Calculadora de Molaridad

Ingresa dos de tres valores (molaridad, masa, volumen) para calcular el tercero. Incluye base de datos de pesos moleculares de reactivos comunes y conversión entre unidades de concentración.

Common Reagents

Molecular Weight (MW)

g/mol

Mass

Volume

Concentration

0.1 mol/L

Result

Mass:5.844 g

Moles:0.1 mol

Volume:1 L

Concentration:0.1 M

Mass/Volume:5.844 g/L

Formula Reference

C (mol/L) = n / V = m / (MW × V)

m (g) = C × V × MW

n (mol) = m / MW

V (L) = m / (C × MW)

¿Tienes una sugerencia?

Solicita una nueva herramienta o sugiere mejoras — ¡únete a nuestra comunidad en Slack!

Dejar feedback en Slack

What is a Molarity Calculator?

A molarity calculator helps scientists and students determine the concentration of a solution in moles per liter (mol/L or M). Molarity is defined as the number of moles of solute per liter of solution: C = n/V = m/(MW × V), where C is concentration (M), n is moles, m is mass (g), MW is molecular weight (g/mol), and V is volume (L). This tool also converts between common concentration units used in laboratories: molarity (M, mM, µM), mass concentration (g/L, mg/mL, µg/mL), percent weight/volume (%(w/v)), parts per million (ppm), parts per billion (ppb), and normality (N).

How to Use This Calculator

Select a common reagent preset or enter your molecular weight manually
In Calculator mode: enter any 2 of mass (g), volume (L), and concentration (M) to solve for the unknown
In Unit Converter mode: enter a concentration value and select the input unit
All other concentration units are calculated automatically in real-time
Use the result table to find the equivalent concentration in your desired unit

Frequently Asked Questions

How do I calculate how much solute to weigh for a solution?

Use the Calculator mode: enter the desired concentration (e.g., 1 M), the total volume you need (e.g., 0.5 L), and the molecular weight of your solute. Set 'Mass' as the solve-for variable. The calculator will tell you exactly how many grams to weigh. For example, for 500 mL of 1 M NaCl (MW 58.44), you need 29.22 g.

What is the difference between molarity and normality?

Molarity (M) measures moles of solute per liter of solution. Normality (N) measures equivalents per liter, where N = M × valence (number of H+ or OH- ions, or electrons transferred). For monovalent compounds like NaCl or HCl, molarity equals normality. For H₂SO₄ (valence 2), 1 M = 2 N.

How do I convert between mg/mL and molarity?

To convert mg/mL to molarity: divide by the molecular weight (in g/mol), then multiply by 1000. Or simply use our Unit Converter mode — enter your value in g/L (which equals mg/mL) and see the molarity instantly. For example, 10 mg/mL of NaCl (MW 58.44) = 0.171 M.

What does %(w/v) mean and how is it related to g/L?

Percent weight/volume (%(w/v)) means grams of solute per 100 mL of solution. To convert %(w/v) to g/L, multiply by 10. For example, 0.9% NaCl (physiological saline) = 9 g/L = 0.154 M. Our converter handles this automatically along with ppm, ppb, and other units.