Acetone Density: 0.791 g/mL at 20 °C, by Source

Short answer: acetone (CAS 67-64-1) has a liquid density of about 0.79 g/mL (equal to 0.79 g/cm³) at 20 °C. The commonly cited values run from 0.7845 to 0.793 g/mL at 20 °C depending on the reference, so a calculation should state which value and which temperature it uses. This page is a lab-solvent datasheet: density by source, the related properties people look up alongside it, and a worked mass-from-volume check.

Density of acetone by source and temperature

PubChem’s Density section for acetone (compound CID 180, read 2026-11-07) collects values from several databases rather than one agreed number. They are close, but not identical:

Value	Stated temperature	Source as listed in PubChem
0.791 g/mL	20 °C	CAMEO Chemicals / CHRIS; also PAC (US DOE)
0.7845 g/cm³	20 °C	HSDB, citing CRC Handbook of Chemistry and Physics, 95th ed.
0.790 to 0.793	20 °C	JECFA
0.79	not stated in the record	NIOSH
0.8 (relative density, water = 1, unitless)	not stated in the record	ICSC

Because 1 mL is defined as 1 cm³, g/mL and g/cm³ are the same unit for density. The roughly 0.8 percent spread between 0.7845 and 0.791 is a difference between references, and this page does not rank them: record the source and temperature next to whichever number you use. For acetone at 25 °C, use a value that a reference states for 25 °C; none of the records above does, so none is quoted here.

Related properties of acetone

Boiling point and freezing point

The NIST Chemistry WebBook (read 2026-11-07) gives a boiling temperature of 329.3 ± 0.3 K (56.15 °C), an average of 117 of 129 reported values, and a fusion (freezing) temperature of 178.7 ± 0.9 K (about -94.45 °C). Its triple point is 178.5 K. Acetone’s boiling point sits close to ambient temperature, so it evaporates readily from open vessels. Note that the NIST page does not list liquid density, which is why the density table above relies on PubChem’s compiled records.

Vapor pressure

Temperature	Vapor pressure	Source
20 °C	180 mmHg (ICSC gives 24 kPa)	CAMEO, PAC, OSHA, NIOSH; ICSC
25 °C	231 mmHg	HSDB
30 °C	270 mmHg	CAMEO, citing NTP 1992

NIST also lists Antoine coefficients for acetone (log₁₀P = A – B/(T + C), P in bar, T in K; A = 4.42448, B = 1312.253, C = -32.445), valid from 259.16 to 507.60 K (Ambrose and Sprake, 1974). At 298.15 K that gives log₁₀P = 4.42448 – 1312.253/265.705 = -0.514, so P is about 0.306 bar (about 30.6 kPa), consistent with the 231 mmHg (30.8 kPa) listed for 25 °C. The enthalpy of vaporization is listed as 29.1 kJ/mol at the boiling point (329.3 K) and 31.27 kJ/mol as the standard value (Majer and Svoboda, 1985).

Viscosity

HSDB, citing Kirk-Othmer, lists a dynamic viscosity of 0.32 cP at 20 °C and 0.27 cP at 40 °C. ICSC card 0087 gives a kinematic viscosity of 0.34 mm²/s at 40 °C. Dynamic and kinematic viscosity are different quantities (kinematic is dynamic divided by density) and should not be swapped between tables.

pKa

HSDB lists a pKa of 20 for acetone, citing Serjeant and Dempsey (IUPAC Chemical Data Series 23, 1979). That describes the very weak acidity of its C-H bonds, not an aqueous acid-base behaviour you would see at the bench.

Refractive index, dielectric constant, polarity index and miscibility are also searched alongside density; they are properties given in solvent-property compilations and are not tabulated on this page.

Using the number at the bench: a mass-from-volume check

When a protocol gives acetone by volume but a balance gives mass, the conversion is mass = density × volume. For 250 mL:

With 0.791 g/mL (20 °C, CAMEO/CHRIS): 0.791 × 250 = 197.75 g.
With 0.7845 g/mL (20 °C, CRC via HSDB): 0.7845 × 250 = 196.1 g.

The two differ by about 1.65 g, or 0.8 percent. For a rinse that difference is immaterial; for a quantitative preparation, record which reference and temperature you used and keep them constant between batches. A checklist:

Write down the density value, its source and its temperature.
Keep units consistent (g/mL = g/cm³; relative density is unitless).
Do not reuse a 20 °C value for a solution or a different temperature without a reference for that condition.
Remember that with a vapor pressure of 180 mmHg at 20 °C, open containers lose volume quickly, so weigh closed or promptly.

Handling data (flammability classification, exposure limits, storage) belongs to the safety data sheet: see how to read an acetone SDS and flammable liquid storage cabinet requirements. For container material compatibility see the chemical resistance chart for plastics.

Common misunderstandings

“Acetone density is one fixed number.” Reference values at 20 °C span 0.7845 to 0.793 g/mL; density also changes with temperature.
“Relative density and density are the same.” ICSC’s 0.8 is relative to water and has no unit; it is rounded to one figure.
“g/mL and g/cm³ differ.” They are identical.
“Dynamic and kinematic viscosity are interchangeable.” They are not; one is divided by density.

FAQ

What is the density of acetone in g/mL?

About 0.79 g/mL at 20 °C; CAMEO/CHRIS lists 0.791 and the CRC value cited by HSDB is 0.7845.

Is acetone density in g/cm³ different from g/mL?

No. 1 mL equals 1 cm³, so the number is the same.

What is acetone’s boiling point?

329.3 ± 0.3 K, or 56.15 °C, per the NIST Chemistry WebBook.

What is acetone’s vapor pressure?

180 mmHg at 20 °C, 231 mmHg at 25 °C and 270 mmHg at 30 °C in the sources listed above.

What is the freezing (melting) point of acetone?

178.7 ± 0.9 K (about -94.45 °C) per NIST; the triple point is 178.5 K.

What is the pKa of acetone?

20, per HSDB citing Serjeant and Dempsey (1979).

For a comparable solvent datasheet, see ethyl acetate density and hexane boiling point.

Sources

NIST Chemistry WebBook, acetone (C67641), phase-change and vapor-pressure data: webbook.nist.gov, read 2026-11-07.
PubChem, acetone (CID 180): Density, Vapor Pressure, Viscosity and Dissociation Constants sections, with the underlying CAMEO, HSDB, ICSC, JECFA, NIOSH and OSHA records: pubchem.ncbi.nlm.nih.gov/compound/180, read 2026-11-07.

Information on this page is general reference data for laboratory staff, not a substitute for the supplier’s safety data sheet.

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