Molarity to Mass/Volume Calculator
Find out exactly how many grams of a solid solute you need to weigh out to make a chemical solution of a target concentration and volume.
Target Formulation
Input concentration, molecular weight, and target volume.
Required Solute Mass
* Weigh out this amount and dissolve up to target volume.
Order of Operations
When preparing buffers, adjust the pH *before* adding the remaining solvent to reach the final volume mark.
Common Lab Buffer Solute Mass Quick Reference Table
| Reagent Solute | MW (g/mol) | Target Conc & Vol | Mass to Weigh |
|---|---|---|---|
| NaCl (Saline) | 58.44 | 154 mM in 1.0 L (PBS / Normal Saline) | 9.00 g |
| Tris-HCl | 157.60 | 50 mM in 500 mL | 3.94 g |
| EDTA | 372.24 | 10 mM in 100 mL (TE buffer component) | 0.372 g (372.2 mg) |
Methodology & Equations
Solute Mass Formula
Rearranges molarity ($M = n / V$) to calculate exact mass ($m = n \times MW$).
Unit Conversion Multipliers
Concentrations in mM are divided by $1,000$; μM divided by $1,000,000$. Milliliters (mL) divided by $1,000$ to convert to Liters.
Frequently Asked Questions
How do I calculate mass required from target Molarity? ▼
Mass (g) = Molarity (mol/L) × Solution Volume (L) × Molecular Weight (g/mol).
What if my target concentration is in millimolar (mM)? ▼
Divide the concentration by 1,000 to convert to Molar (M) before performing the calculation (e.g. 50 mM = 0.050 M).
Should I add the solid directly to the final volume of solvent? ▼
No. Dissolve the solid solute in about 80% of your target volume first, then bring the total solution volume up to the final mark. Dissolving solute alters total liquid volume.
Related Calculators
View All Biology Tools →Molarity Calculator
Calculate the molarity of a solution from solute mass and volume.
Molality Calculator
Determine solution molality (mol/kg solvent).
Buffer Recipe Calculator
Calculate acid and base components for a specific pH buffer.