Heat-transfer fluids

Methanol · CH3OH

Name: Methanol (CH3OH) aqueous solution properties
Creator: ProcessConvert
License: https://creativecommons.org/licenses/by/4.0/

Methanol (CH3OH) is a coolant; this page gives computed density, dynamic viscosity and specific heat capacity for aqueous solutions from 10–50 wt% and -45–40 °C.

Values are computed from CoolProp's incompressible aqueous-mixture correlation (Melinder, 2010) and tabulated over 10–50 wt% and -45–40 °C.

Also known as: Methyl alcohol, Wood alcohol, Carbinol, MeOH
CAS number: 67-56-1
Tabulated range: 10–50 wt% · -45–40 °C
Properties: Density · Dynamic viscosity · Specific heat capacity · Specific gravity

At 20 wt% · 20 °C

reference snapshot

Density: 966.8kg/m³
Density: 0.9668g/cm³
Specific gravity: 0.969
Viscosity: 1.598cP
Specific heat: 4110J/kg·K

Explore

Read a value at any point

Move the sliders to interpolate between the tabulated grid points. The readout and chart never go outside the validated 10–50 wt% and -45–40 °C range, and every number is interpolated from the committed table below — nothing is computed from a chemistry model in your browser.

Interactive explorer

Values are interpolated between the tabulated grid points below — sliders stay within the validated 10–50 wt% and -45–40 °C range.

Concentration30 wt%

Temperature20 °C

Density: 951.5 kg/m³
Density: 0.9515 g/cm³
Specific gravity: 0.953
Dynamic viscosity: 1.789 cP
Specific heat: 3986 J/kg·K

Density (kg/m³) vs wt% CH3OH at 20 °C — Methanol.

Why it matters

What the numbers tell you

At 20 wt% and 20 °C, aqueous methanol has a density of about 967 kg/m³ (0.967 g/cm³) — roughly 0.97× the density of water. It also has a dynamic viscosity of about 1.598 cP, against roughly 1 cP for water at the same temperature, and a specific heat of about 4.11 kJ/kg·K, about 98% of water’s 4.18 kJ/kg·K. Those differences carry straight into volume-to-mass conversions, pump and pipe sizing, and the heat needed to change its temperature.

Common grades

A few working strengths

Properties at 20 °C for a handful of concentrations in everyday use, read from the committed grid (interpolated between tabulated points where a grade falls between them). The full table follows below.

wt% CH3OH	°C	Density kg/m³	SG	Viscosity cP	Sp. heat J/kg·K
20	20	966.8	0.969	1.598	4110
30	20	951.5	0.953	1.789	3986
40	20	934.6	0.936	1.839	3822
50	20	915.7	0.917	1.762	3603

Freezing point

How low it protects

Freezing point of the aqueous solution against strength, computed from the same correlation and checked against an independently cited value. A 50 wt% methanol solution freezes at about −54.5 °C.

wt% CH3OH	Freezing point °C
10	−6.5
15	−10.6
20	−15.1
25	−20.1
30	−25.7
35	−31.9
40	−38.7
45	−46.2
50	−54.5

Freeze check: 20 wt% computed −15.1 °C against a cited −15.0 °C (tolerance ±1.5 °C). CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions. CRC Handbook of Chemistry and Physics, Concentrative Properties of Aqueous Solutions, Methanol table: 20.0 mass % methanol at 20 degC, freezing point depression = 15.02 degC (freezing point about -15.0 degC). The CRC freezing-point-depression column agrees with the Melinder freeze curve underlying CoolProp's INCOMP::MMA to within 0.1 degC across this range.

Sources

Where the numbers come from

Every value on this page is computed by a deterministic model — none is entered by hand. The generating method and the references it is checked against:

▸Melinder, A. (2010). Properties of Secondary Working Fluids for Indirect Systems, 2nd ed. International Institute of Refrigeration - the basis of CoolProp's incompressible aqueous methanol (INCOMP::MMA) correlation.
▸CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions (density, freezing-point depression and viscosity at 20 degC; primary data Wolf 1966, Sohnel & Novotny 1985)

Model: CoolProp==6.6.0 - incompressible aqueous MMA correlation (Melinder 2010) · Generated 2026-06-07

The committed data file for this page is published as JSON on GitHub under CC BY 4.0.

Validation

Checked against a cited value

The model is cross-checked at one independently cited reference point. The page is published only because this check passes.

Property / point	Density · 20 wt% · 20 °C
Cited reference value	966.6 kg/m3
Model computed	966.79 kg/m3
Error vs reference	0.019% (tolerance 1%)

CRC Handbook of Chemistry and Physics - Concentrative Properties of Aqueous Solutions. CRC Handbook of Chemistry and Physics, Concentrative Properties of Aqueous Solutions: Density, Refractive Index, Freezing Point Depression, and Viscosity (all data at 20 degC; primary data Wolf 1966, Sohnel & Novotny 1985), Methanol table: 20.0 mass % methanol at 20 degC = 0.9666 g/cm3. This measured handbook data is independent of the Melinder correlation underlying CoolProp's INCOMP::MMA, so the check is a genuine cross-validation.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% CH3OH). Read the cell at the intersection. Specific gravity is density divided by the model water reference of 998.2 kg/m³ at 20 °C.

Cells left blank (—) sit below the solution's freezing point at that strength, where it is no longer liquid; those points are not tabulated and the explorer will not interpolate across them.

Density — kg/m³

°C \ wt%	10	15	20	25	30	35	40	45	50
-45	—	—	—	—	—	—	—	962.0	955.7
-40	—	—	—	—	—	—	—	959.4	952.8
-35	—	—	—	—	—	—	962.7	956.9	949.9
-30	—	—	—	—	—	965.7	960.5	954.2	947.0
-25	—	—	—	—	968.5	963.9	958.2	951.6	944.0
-20	—	—	—	971.5	967.1	961.9	955.8	948.8	941.0
-15	—	—	974.9	970.5	965.6	959.9	953.4	946.1	938.0
-10	—	979.1	974.3	969.3	963.9	957.8	950.9	943.3	934.9
-5	984.5	978.8	973.5	968.0	962.1	955.6	948.4	940.4	931.8
0	984.4	978.3	972.5	966.6	960.2	953.3	945.7	937.5	928.6
5	984.1	977.6	971.4	965.0	958.2	950.9	943.0	934.6	925.5
10	983.5	976.6	970.0	963.2	956.1	948.5	940.3	931.6	922.2
15	982.6	975.5	968.5	961.3	953.8	945.9	937.5	928.5	919.0
20	981.5	974.1	966.8	959.3	951.5	943.3	934.6	925.4	915.7
25	980.2	972.6	964.9	957.1	949.0	940.5	931.6	922.2	912.4
30	978.7	970.8	962.9	954.8	946.4	937.7	928.6	919.0	909.0
35	977.0	968.9	960.7	952.4	943.7	934.8	925.5	915.8	905.6
40	975.0	966.7	958.4	949.8	940.9	931.7	922.3	912.5	902.2

Dynamic viscosity — cP (mPa·s)

°C \ wt%	10	15	20	25	30	35	40	45	50
-45	—	—	—	—	—	—	—	35.62	30.27
-40	—	—	—	—	—	—	—	25.56	22.06
-35	—	—	—	—	—	—	20.86	18.74	16.41
-30	—	—	—	—	—	16.39	15.40	14.01	12.44
-25	—	—	—	—	12.40	12.21	11.60	10.68	9.603
-20	—	—	—	9.071	9.356	9.283	8.899	8.287	7.541
-15	—	—	6.449	6.946	7.195	7.187	6.950	6.538	6.017
-10	—	4.497	5.030	5.421	5.635	5.662	5.518	5.240	4.873
-5	3.107	3.582	3.996	4.308	4.490	4.534	4.450	4.261	4.000
0	2.535	2.905	3.230	3.480	3.635	3.686	3.640	3.512	3.326
5	2.103	2.395	2.653	2.855	2.986	3.039	3.017	2.931	2.797
10	1.771	2.004	2.211	2.377	2.487	2.538	2.531	2.473	2.376
15	1.512	1.700	1.868	2.004	2.097	2.144	2.146	2.108	2.038
20	1.307	1.460	1.598	1.710	1.789	1.832	1.839	1.813	1.762
25	1.143	1.268	1.382	1.474	1.541	1.579	1.589	1.572	1.534
30	1.008	1.112	1.206	1.284	1.340	1.373	1.383	1.372	1.343
35	0.897	0.984	1.062	1.127	1.174	1.203	1.212	1.205	1.182
40	0.803	0.876	0.942	0.996	1.036	1.060	1.068	1.063	1.044

Specific heat capacity — J/kg·K

°C \ wt%	10	15	20	25	30	35	40	45	50
-45	—	—	—	—	—	—	—	2982	2874
-40	—	—	—	—	—	—	—	3056	2947
-35	—	—	—	—	—	—	3242	3129	3018
-30	—	—	—	—	—	3435	3312	3199	3088
-25	—	—	—	—	3633	3499	3380	3268	3155
-20	—	—	—	3828	3687	3561	3445	3334	3220
-15	—	—	4006	3868	3738	3619	3507	3397	3282
-10	—	4154	4030	3905	3786	3674	3566	3456	3341
-5	4251	4159	4050	3938	3830	3725	3621	3512	3396
0	4241	4163	4068	3969	3870	3772	3671	3563	3447
5	4230	4165	4083	3996	3907	3815	3717	3610	3494
10	4219	4165	4095	4019	3938	3852	3758	3652	3535
15	4208	4164	4104	4037	3965	3885	3793	3688	3572
20	4198	4161	4110	4052	3986	3911	3822	3719	3603
25	4187	4156	4112	4062	4003	3932	3845	3743	3628
30	4177	4149	4111	4067	4013	3946	3862	3760	3646
35	4168	4141	4107	4066	4017	3953	3871	3771	3658
40	4159	4130	4098	4061	4014	3953	3873	3774	3662

Typical values

Methanol solution properties at 25 °C

At 25 °C, 20 wt% methanol has a density of about 964.9 kg/m³, a dynamic viscosity of about 1.382 cP and a specific heat capacity of about 4112 J/kg·K. At 25 °C, 40 wt% methanol has a density of about 931.6 kg/m³, a dynamic viscosity of about 1.589 cP and a specific heat capacity of about 3845 J/kg·K. At 25 °C, 50 wt% methanol has a density of about 912.4 kg/m³, a dynamic viscosity of about 1.534 cP and a specific heat capacity of about 3628 J/kg·K.

Limitations

Before you use these numbers

▸CoolProp's incompressible aqueous methanol correlation (INCOMP::MMA), built on Melinder (2010). Tabulated for 10-50 wt% methanol over -45 to 40 degC. Methanol is a non-electrolyte freeze-protection brine, so it is modelled with CoolProp rather than the Laliberte electrolyte correlation. Each cell sits above the solution's freezing line at that strength: cells below it (where the solution is no longer liquid) are left blank rather than tabulated, and the explorer will not interpolate across them. Methanol is volatile and flammable, so closed handling is assumed. Values are for preliminary design; verify against vendor data for critical service.
▸Values are tabulated only inside the 10–50 wt% and -45–40 °C ranges shown; the correlation is not extrapolated beyond them here.
▸Figures are for a pure methanol–water system. Commercial grades contain impurities (for example chloride in some caustic grades) that shift density and viscosity; check the supplier's data sheet for a specific product.
▸Use for preliminary design; verify for critical service.

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