Heat-transfer fluids

Propylene glycol · C3H8O2

Density, dynamic viscosity and specific heat capacity of aqueous propylene glycol as a function of concentration and temperature, computed from CoolProp's incompressible aqueous-mixture correlation (Melinder, 2010). Tabulated over 10–60 wt% and 0–100 °C.

Also known as: MPG, Monopropylene glycol, 1,2-Propanediol, Propane-1,2-diol
CAS number: 57-55-6
Tabulated range: 10–60 wt% · 0–100 °C
Properties: Density · Dynamic viscosity · Specific heat capacity · Specific gravity

At 40.94 wt% · 20 °C

reference snapshot

Density: 1033.0kg/m³
Density: 1.0330g/cm³
Specific gravity: 1.035
Viscosity: 4.558cP
Specific heat: 3691J/kg·K

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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 10–60 wt% and 0–100 °C range, and every number is interpolated from the committed table below — nothing is computed from a chemistry model in your browser.

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Values are interpolated between the tabulated grid points below — sliders stay within the validated 10–60 wt% and 0–100 °C range.

Concentration35 wt%

Temperature20 °C

Density: 1028.2 kg/m³
Density: 1.0282 g/cm³
Specific gravity: 1.030
Dynamic viscosity: 3.607 cP
Specific heat: 3786 J/kg·K

Density (kg/m³) vs wt% C3H8O2 at 20 °C — Propylene glycol.

Why it matters

What the numbers tell you

At 40.94 wt% and 20 °C, aqueous propylene glycol has a density of about 1033 kg/m³ (1.033 g/cm³) — roughly 1.03× the density of water. Its dynamic viscosity is about 4.558 cP, against roughly 1 cP for water at the same temperature, and its specific heat is about 3.69 kJ/kg·K — about 88% 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% C3H8O2	°C	Density kg/m³	SG	Viscosity cP	Sp. heat J/kg·K
20	20	1014.8	1.017	2.030	3977
30	20	1023.8	1.026	2.965	3857
40	20	1032.3	1.034	4.384	3707
50	20	1039.1	1.041	6.394	3530

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 propylene glycol (INCOMP::MPG) correlation.
▸Khattab, I.S., Bandarkar, F., Khoubnasabjafari, M., Jouyban, A. (2012). Density, viscosity, surface tension, and molar volume of propylene glycol + water mixtures from 293 to 323 K and correlations by the Jouyban-Acree model. Arabian J. Chem. 10(Suppl. 1), S71-S75 (measured density).

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

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 · 40.94 wt% · 20 °C
Cited reference value	1031.2 kg/m3
Model computed	1033 kg/m3
Error vs reference	0.175% (tolerance 1%)

Khattab et al. (2012), Arabian Journal of Chemistry. Khattab, I.S., Bandarkar, F., Khoubnasabjafari, M., Jouyban, A. (2012). Density, viscosity, surface tension, and molar volume of propylene glycol + water mixtures from 293 to 323 K and correlations by the Jouyban-Acree model. Arabian J. Chem. 10(Suppl. 1), S71-S75. Measured density at 293 K, propylene glycol mole fraction x1 = 0.141 (= 40.94 wt%): 1.0312 g/cm3 = 1031.2 kg/m3. This measured dataset is independent of the Melinder correlation that the CoolProp model is fitted to, so the check is a genuine cross-validation rather than a circular one.

Full tables

Every tabulated point

Rows are temperature (°C); columns are concentration (wt% C3H8O2). Read the cell at the intersection. Specific gravity is density divided by the model water reference of 998.2 kg/m³ at 20 °C.

Density — kg/m³

°C \ wt%	10	15	20	25	30	35	40	45	50	55	60
0	1009.3	1014.5	1020.1	1025.8	1031.6	1037.1	1042.4	1047.0	1050.9	1054.0	1056.0
5	1008.9	1013.9	1019.1	1024.5	1029.9	1035.1	1040.1	1044.5	1048.2	1051.0	1052.9
10	1008.3	1012.9	1017.9	1022.9	1028.0	1033.0	1037.6	1041.8	1045.3	1048.0	1049.7
15	1007.4	1011.8	1016.4	1021.2	1026.0	1030.7	1035.0	1038.9	1042.2	1044.8	1046.4
20	1006.2	1010.4	1014.8	1019.3	1023.8	1028.2	1032.3	1036.0	1039.1	1041.5	1043.0
25	1004.8	1008.8	1012.9	1017.2	1021.4	1025.5	1029.4	1032.9	1035.8	1038.0	1039.5
30	1003.2	1007.0	1010.9	1014.9	1018.9	1022.8	1026.4	1029.7	1032.4	1034.5	1035.9
35	1001.4	1005.0	1008.7	1012.5	1016.2	1019.9	1023.3	1026.3	1028.9	1030.9	1032.2
40	999.4	1002.9	1006.4	1009.9	1013.4	1016.9	1020.1	1022.9	1025.4	1027.2	1028.4
45	997.2	1000.5	1003.9	1007.2	1010.5	1013.7	1016.7	1019.5	1021.7	1023.5	1024.6
50	994.9	998.1	1001.2	1004.4	1007.5	1010.5	1013.3	1015.9	1018.0	1019.7	1020.7
55	992.4	995.5	998.5	1001.4	1004.4	1007.2	1009.9	1012.3	1014.3	1015.8	1016.8
60	989.8	992.7	995.6	998.4	1001.2	1003.8	1006.3	1008.6	1010.5	1011.9	1012.8
65	987.1	989.9	992.6	995.3	997.9	1000.4	1002.7	1004.8	1006.6	1008.0	1008.8
70	984.2	987.0	989.5	992.1	994.5	996.8	999.1	1001.0	1002.7	1004.0	1004.8
75	981.3	983.9	986.4	988.8	991.1	993.3	995.4	997.2	998.8	1000.0	1000.8
80	978.2	980.8	983.2	985.4	987.6	989.7	991.6	993.4	994.9	996.0	996.7
85	975.1	977.6	979.9	982.0	984.1	986.0	987.9	989.6	991.0	992.1	992.7
90	971.9	974.4	976.6	978.6	980.5	982.4	984.1	985.7	987.1	988.1	988.7
95	968.7	971.1	973.2	975.2	977.0	978.7	980.4	981.9	983.2	984.2	984.8
100	965.5	967.8	969.9	971.7	973.4	975.1	976.6	978.0	979.3	980.2	980.8

Dynamic viscosity — cP (mPa·s)

°C \ wt%	10	15	20	25	30	35	40	45	50	55	60
0	2.745	3.417	4.312	5.515	7.117	9.212	11.88	15.17	19.11	23.73	29.17
5	2.290	2.812	3.494	4.393	5.569	7.083	8.982	11.30	14.05	17.29	21.15
10	1.936	2.347	2.875	3.558	4.438	5.554	6.935	8.604	10.58	12.90	15.71
15	1.656	1.985	2.399	2.928	3.598	4.437	5.463	6.691	8.140	9.852	11.95
20	1.432	1.699	2.030	2.445	2.965	3.607	4.384	5.307	6.394	7.683	9.279
25	1.252	1.472	1.739	2.071	2.480	2.980	3.580	4.288	5.120	6.112	7.354
30	1.105	1.288	1.508	1.776	2.104	2.501	2.972	3.526	4.175	4.953	5.938
35	0.984	1.139	1.321	1.542	1.808	2.128	2.505	2.945	3.461	4.082	4.877
40	0.884	1.016	1.169	1.353	1.573	1.834	2.141	2.497	2.914	3.418	4.068
45	0.799	0.913	1.044	1.199	1.383	1.600	1.853	2.146	2.488	2.902	3.442
50	0.728	0.827	0.940	1.073	1.229	1.412	1.623	1.866	2.151	2.496	2.950
55	0.667	0.754	0.852	0.967	1.101	1.257	1.436	1.642	1.881	2.172	2.556
60	0.614	0.691	0.778	0.878	0.995	1.129	1.283	1.458	1.661	1.909	2.236
65	0.567	0.636	0.714	0.802	0.904	1.022	1.155	1.306	1.480	1.692	1.972
70	0.526	0.588	0.657	0.736	0.827	0.931	1.047	1.178	1.328	1.510	1.752
75	0.490	0.546	0.608	0.679	0.760	0.852	0.955	1.069	1.199	1.356	1.563
80	0.456	0.507	0.564	0.628	0.701	0.783	0.874	0.975	1.088	1.223	1.401
85	0.426	0.472	0.524	0.582	0.648	0.722	0.803	0.892	0.990	1.106	1.258
90	0.397	0.440	0.487	0.540	0.600	0.667	0.740	0.818	0.903	1.002	1.130
95	0.371	0.410	0.453	0.502	0.557	0.617	0.682	0.751	0.824	0.908	1.015
100	0.346	0.381	0.420	0.465	0.515	0.570	0.628	0.689	0.752	0.822	0.909

Specific heat capacity — J/kg·K

°C \ wt%	10	15	20	25	30	35	40	45	50	55	60
0	4059	3997	3936	3872	3803	3726	3642	3550	3453	3352	3250
5	4062	4004	3946	3884	3816	3741	3658	3568	3472	3373	3272
10	4067	4012	3956	3896	3830	3756	3674	3586	3492	3394	3295
15	4071	4020	3966	3908	3843	3771	3691	3603	3511	3415	3318
20	4076	4028	3977	3920	3857	3786	3707	3621	3530	3436	3340
25	4082	4036	3987	3933	3870	3800	3723	3639	3549	3457	3363
30	4088	4045	3998	3945	3884	3815	3739	3656	3569	3478	3386
35	4094	4054	4008	3957	3897	3830	3755	3674	3588	3499	3408
40	4101	4063	4019	3969	3910	3844	3771	3691	3607	3520	3431
45	4108	4072	4030	3981	3924	3859	3787	3709	3626	3541	3453
50	4115	4081	4040	3992	3937	3873	3802	3726	3645	3561	3476
55	4123	4090	4051	4004	3950	3887	3818	3743	3664	3582	3498
60	4130	4099	4061	4016	3962	3901	3834	3761	3683	3603	3521
65	4138	4108	4071	4027	3975	3915	3849	3778	3703	3624	3543
70	4146	4117	4082	4039	3988	3929	3865	3795	3722	3645	3565
75	4153	4126	4092	4050	4000	3943	3880	3813	3741	3666	3588
80	4161	4135	4102	4061	4012	3957	3896	3830	3760	3686	3610
85	4169	4144	4111	4071	4024	3971	3911	3847	3779	3707	3632
90	4176	4152	4121	4082	4036	3984	3926	3864	3798	3728	3654
95	4183	4160	4130	4092	4048	3997	3942	3881	3817	3749	3676
100	4190	4168	4139	4103	4060	4011	3957	3898	3836	3769	3698

Limitations

Before you use these numbers

▸CoolProp's incompressible aqueous propylene glycol correlation (INCOMP::MPG), built on Melinder (2010). Tabulated for 10-60 wt% MPG over 0-100 degC, inside the correlation's validated window; values are not extrapolated beyond it. Propylene glycol is a non-electrolyte, so it is modelled with CoolProp rather than the Laliberte electrolyte correlation used for the acids and bases. Propylene glycol is markedly more viscous than ethylene glycol at the same strength, which matters for pump and pressure-drop work. Figures are for a pure propylene glycol-water system; inhibited commercial and food-grade fluids carry additives that shift density, viscosity and freezing point, so check the supplier's data sheet for a specific product. Values are for preliminary design; verify against vendor data for critical service.
▸Values are tabulated only inside the 10–60 wt% and 0–100 °C ranges shown; the correlation is not extrapolated beyond them here.
▸Figures are for a pure propylene glycol–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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