Solution Density Calculator
The density of a solution is its mass divided by its volume (rho = m/V). In analytical chemistry, density is essential for converting between mass-based concentrations (like mass percent or molality) and volume-based concentrations (like molarity). This calculator accepts mass in grams and volume in milliliters to give density in g/mL, and also shows the equivalent values in g/L and kg/L. You can also enter density and volume to find mass, or density and mass to find volume.
Solution density formula
rho (g/mL) = mass (g) / volume (mL) rho (g/L) = rho (g/mL) * 1000 rho (kg/L) = rho (g/mL) / 1000
Density is temperature-dependent. All density values should be reported with the measurement temperature (typically 20 degrees C or 25 degrees C for lab solutions).
Common solution densities at 20 degrees C
- Pure water: 0.998 g/mL.
- Seawater (3.5% salinity): approximately 1.025 g/mL.
- Concentrated hydrochloric acid (37% w/w): 1.19 g/mL.
- Concentrated sulfuric acid (98% w/w): 1.84 g/mL.
- Ethanol (absolute, 100%): 0.789 g/mL.
Frequently asked questions
What is the density of a solution?
The density of a solution is its mass per unit volume, typically expressed in g/mL (equivalent to g/cm^3) for laboratory solutions. Density tells you how concentrated a solution is by mass per volume.
How does solute concentration affect solution density?
Dissolving a solute denser than the solvent increases the density of the solution. For example, aqueous sodium chloride is denser than pure water (1.00 g/mL). The more solute dissolved, the higher the density.
How is density used to find concentration?
Knowing density and mass percent, you can calculate molarity: M = (density * 10 * w%) / molar mass, where density is in g/mL and w% is the mass percent. This is commonly used with commercial concentrated acids.
What is the density of water at different temperatures?
Pure water has a maximum density of 1.00000 g/mL at 3.98 degrees C. At 20 degrees C it is 0.99821 g/mL. At 25 degrees C it is 0.99705 g/mL. Density decreases above and below the maximum.
How do I measure solution density in the lab?
The most common lab methods are: weigh a known volume (e.g., in a volumetric flask or pycnometer); or use a digital density meter (oscillating U-tube). Hydrometers give quick approximate readings for many solutions.
Official sources
- IUPAC Gold Book: Density definition.
- NIST Chemistry WebBook: NIST fluid properties.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.