Molarity Calculator

Molarity From Percentage Calculator

This molarity from percentage calculator converts weight/volume percent (% w/v) or weight/weight percent (% w/w) to molar concentration. Enter the percentage, density (for w/w%), and molar mass to get molarity instantly.

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Molarity From Percentage Calculator

Percentage → Molarity

Formula
M = (% × 10 × density) / MW
Live Preview
Percentage (%)
Density (for w/w)
Molar Mass
Molarity (M)
How It Works
1
Percentage (%)
Enter value
2
Density (for w/w)
Enter value
3
Molar Mass
Enter value
Molarity (M)

What is Molarity From Percentage?

Molarity from percentage converts percentage-based concentration (w/v% or w/w%) to moles per liter. Many commercial reagents and pharmaceutical formulations express concentration as a percentage.

For % w/v: the percentage means grams per 100 mL of solution. For % w/w: the percentage means grams per 100 grams of solution (density is needed to convert to volume).

Understanding percentage-to-molarity conversion is essential for preparing solutions from commercial reagents (e.g., 37% HCl, 70% HNO₃, 30% H₂O₂) and for pharmaceutical compounding.

Molarity = (% × 10 × density) ÷ molar mass
Visual Concept
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Percentage → Molarity
Concentration measured in moles per liter (mol/L)
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Unit: M (Molar)
1 M = 1 mol of solute per 1 liter of solution
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Key Relationship
Molarity = Moles of Solute ÷ Volume of Solution

Molarity From Percentage Formula

The formula for calculating molarity from percentage:

molarity = moles of solute ÷ volume of solution (L)

To use this formula, you need percentage, density, and molar mass. The calculator handles all unit conversions automatically.

Enter your values below to see the molarity from percentage formula in action.

mass ÷ volume = concentration = molarity × molar mass

Where mass is in grams (g), volume is in liters (L), and molar mass is in g/mol.

Formula Breakdown
M = (% × ρ × 10) / MW
M
Molarity (mol/L)
%
Mass percentage (%)
ρ
Density (g/mL)
MW
Molar mass (g/mol)
💡 Converts weight/weight percentage to molar concentration

How to Calculate Molarity From Percentage

Follow these steps to calculate molarity from percentage:

  1. Identify the percentage of your solute and gather all known values.
  2. Find the molar mass of the substance from the periodic table or a chemical database.
  3. Enter your percentage value and select the appropriate unit from the dropdown.
  4. Enter the volume of the solution in liters (L) or select another volume unit.
  5. Click Calculate to get the molarity result instantly.
  6. Verify the result using the step-by-step breakdown provided by the calculator.
Step-by-Step Process
1
📊
Get Percentage
Find mass/mass percentage (% w/w)
2
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Get Density
Find solution density (g/mL)
3
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Find MW
Look up molar mass of solute
4
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Calculate
M = (% × ρ × 10) / MW
5
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Verify
Double-check units and calculation
6
Result
Molarity in mol/L

Molarity From Percentage Calculator Examples

The examples below show how to use the molarity from percentage calculator in practice.

Example 1: What is the molarity of 37% HCl? 37% w/w HCl, density 1.19 g/mL, molar mass 36.46 g/mol → M = (37 × 10 × 1.19) / 36.46 ≈ 12.08 M.

Example 2: Using the formula: molarity = moles ÷ volume, compute the result and verify with the calculator above.

Example 3: Enter your own values into the calculator to see personalized step-by-step results.

Worked Example Example: 37% HCl
Percentage 37 %
Density 1.19 g/mL
MW 36.46 g/mol
Molarity 12.08 M

Molarity Calculator Tools

Explore our collection of 20 specialized molarity calculators. Each tool is designed for a specific type of calculation with its own unique input fields and formulas.

FAQs

How do you convert % to molarity?

For % w/v: M = (% × 10) ÷ molar mass. For % w/w: M = (% × 10 × density) ÷ molar mass.

What is the molarity of 37% HCl?

37% w/w HCl, density 1.19 g/mL, molar mass 36.46 g/mol → M = (37 × 10 × 1.19) / 36.46 ≈ 12.08 M.

What is the difference between w/v% and w/w%?

w/v% = grams of solute per 100 mL of solution. w/w% = grams of solute per 100 g of solution.

What units does the Molarity From Percentage Calculator support?

The molarity from percentage calculator supports mass units (g, mg, µg, kg), volume units (L, mL, µL, gal), molar mass (g/mol, kg/mol), and molarity units (M, mM, µM, nM, pM, fM, aM).

Is the Molarity From Percentage Calculator free to use?

Yes. The molarity from percentage calculator is 100% free, requires no sign-up, and works on all devices. All calculations are performed instantly in your browser.