R-404A pressure-temperature chart

Gauge pressure at sea level. Liquid (bubble) pressure is the one to use for subcooling and vapor (dew) pressure for superheat.

°F and psig°C and kPa

R-404A saturation pressure by temperature, °F and psig
°F	Liquid (bubble) psig	Vapor (dew) psig
-40	4.9	4.3
-39	5.4	4.8
-38	5.9	5.3
-37	6.4	5.8
-36	7.0	6.3
-35	7.5	6.8
-34	8.0	7.4
-33	8.6	7.9
-32	9.2	8.5
-31	9.7	9.0
-30	10.3	9.6
-29	10.9	10.2
-28	11.5	10.8
-27	12.2	11.4
-26	12.8	12.0
-25	13.4	12.7
-24	14.1	13.3
-23	14.8	14.0
-22	15.4	14.6
-21	16.1	15.3
-20	16.8	16.0
-19	17.5	16.7
-18	18.3	17.4
-17	19.0	18.2
-16	19.8	18.9
-15	20.5	19.7
-14	21.3	20.4
-13	22.1	21.2
-12	22.9	22.0
-11	23.7	22.8
-10	24.6	23.6
-9	25.4	24.5
-8	26.3	25.3
-7	27.1	26.2
-6	28.0	27.0
-5	28.9	27.9
-4	29.8	28.8
-3	30.8	29.8
-2	31.7	30.7
-1	32.7	31.6
0	33.7	32.6
1	34.7	33.6
2	35.7	34.6
3	36.7	35.6
4	37.7	36.6
5	38.8	37.7
6	39.8	38.7
7	40.9	39.8
8	42.0	40.9
9	43.1	42.0
10	44.3	43.1
11	45.4	44.3
12	46.6	45.4
13	47.8	46.6
14	49.0	47.8
15	50.2	49.0
16	51.5	50.2
17	52.7	51.5
18	54.0	52.7
19	55.3	54.0
20	56.6	55.3
21	57.9	56.6
22	59.3	57.9
23	60.6	59.3
24	62.0	60.7
25	63.4	62.1
26	64.8	63.5
27	66.3	64.9
28	67.8	66.4
29	69.2	67.8
30	70.7	69.3
31	72.3	70.8
32	73.8	72.4
33	75.4	73.9
34	77.0	75.5
35	78.6	77.1
36	80.2	78.7
37	81.8	80.3
38	83.5	82.0
39	85.2	83.7
40	86.9	85.4
41	88.6	87.1
42	90.4	88.8
43	92.2	90.6
44	94.0	92.4
45	95.8	94.2
46	97.6	96.0
47	99.5	97.9
48	101.4	99.8
49	103.3	101.7
50	105.3	103.6
51	107.2	105.6
52	109.2	107.5
53	111.2	109.5
54	113.3	111.6
55	115.3	113.6
56	117.4	115.7
57	119.5	117.8
58	121.7	119.9
59	123.8	122.1
60	126.0	124.2
61	128.2	126.4
62	130.4	128.7
63	132.7	130.9
64	135.0	133.2
65	137.3	135.5
66	139.7	137.8
67	142.0	140.2
68	144.4	142.6
69	146.9	145.0
70	149.3	147.4
71	151.8	149.9
72	154.3	152.4
73	156.8	154.9
74	159.4	157.5
75	162.0	160.1
76	164.6	162.7
77	167.3	165.3
78	169.9	168.0
79	172.7	170.7
80	175.4	173.4
81	178.2	176.2
82	181.0	179.0
83	183.8	181.8
84	186.7	184.7
85	189.5	187.5
86	192.5	190.5
87	195.4	193.4
88	198.4	196.4
89	201.4	199.4
90	204.5	202.4
91	207.6	205.5
92	210.7	208.6
93	213.8	211.8
94	217.0	214.9
95	220.2	218.1
96	223.5	221.4
97	226.7	224.6
98	230.0	228.0
99	233.4	231.3
100	236.8	234.7
101	240.2	238.1
102	243.6	241.5
103	247.1	245.0
104	250.7	248.5
105	254.2	252.1
106	257.8	255.7
107	261.4	259.3
108	265.1	263.0
109	268.8	266.7
110	272.6	270.4
111	276.3	274.2
112	280.2	278.0
113	284.0	281.9
114	287.9	285.8
115	291.8	289.7
116	295.8	293.7
117	299.8	297.7
118	303.9	301.7
119	308.0	305.8
120	312.1	309.9
121	316.3	314.1
122	320.5	318.3
123	324.7	322.6
124	329.0	326.9
125	333.4	331.2
126	337.7	335.6
127	342.2	340.0
128	346.6	344.5
129	351.1	349.0
130	355.7	353.6
131	360.3	358.2
132	364.9	362.8
133	369.6	367.5
134	374.3	372.3
135	379.1	377.1
136	384.0	381.9
137	388.8	386.8
138	393.7	391.7
139	398.7	396.7
140	403.7	401.7
141	408.8	406.8
142	413.9	412.0
143	419.1	417.1
144	424.3	422.4
145	429.6	427.7
146	434.9	433.0
147	440.3	438.4
148	445.7	443.9
149	451.2	449.4
150	456.8	455.0

R-404A saturation pressure by temperature, °C and kPa
°C	Liquid (bubble) kPa	Vapor (dew) kPa
-40	34	30
-39	40	36
-38	47	42
-37	53	49
-36	60	55
-35	67	62
-34	75	70
-33	82	77
-32	90	85
-31	98	93
-30	106	101
-29	115	109
-28	124	118
-27	133	127
-26	143	137
-25	152	146
-24	162	156
-23	173	166
-22	183	177
-21	194	188
-20	206	199
-19	217	210
-18	229	222
-17	242	234
-16	254	247
-15	267	260
-14	281	273
-13	294	286
-12	308	300
-11	323	315
-10	338	329
-9	353	344
-8	369	360
-7	385	376
-6	401	392
-5	418	409
-4	435	426
-3	453	444
-2	471	462
-1	490	480
0	509	499
1	528	518
2	548	538
3	569	558
4	590	579
5	611	600
6	633	622
7	655	644
8	678	667
9	702	691
10	726	714
11	750	739
12	775	764
13	801	789
14	827	815
15	854	842
16	881	869
17	909	896
18	937	925
19	966	954
20	996	983
21	1,026	1,013
22	1,057	1,044
23	1,088	1,075
24	1,120	1,107
25	1,153	1,140
26	1,187	1,173
27	1,221	1,207
28	1,255	1,242
29	1,291	1,277
30	1,327	1,313
31	1,364	1,350
32	1,401	1,387
33	1,440	1,425
34	1,479	1,464
35	1,518	1,504
36	1,559	1,544
37	1,600	1,586
38	1,642	1,627
39	1,685	1,670
40	1,728	1,714
41	1,773	1,758
42	1,818	1,803
43	1,864	1,849
44	1,911	1,896
45	1,958	1,943
46	2,007	1,992
47	2,056	2,041
48	2,106	2,092
49	2,157	2,143
50	2,210	2,195
51	2,263	2,248
52	2,316	2,302
53	2,371	2,357
54	2,427	2,413
55	2,484	2,470
56	2,542	2,528
57	2,601	2,587
58	2,661	2,647
59	2,722	2,708
60	2,784	2,770
61	2,847	2,833
62	2,911	2,898
63	2,977	2,963
64	3,043	3,030
65	3,111	3,099

You're free to reuse this chart's numbers under CC BY 4.0. Just credit Pocket HVAC and link back to this page.

From pockethvac.com/r404a-pt-chart/. Each row is solved at its exact temperature with CoolProp 8.0.0. Free to reuse under CC BY 4.0.

What is an R-404A PT chart?

An R-404A PT chart lists the pressure R-404A boils and condenses at for each temperature. At 40°F that's 85.4 psig on the vapor (dew) side and 86.9 psig on the liquid (bubble) side. It's sold as Forane 404A and Klea 404A, and older cylinders say Freon 404A (Chemours stopped selling it in the US in 2024).

Anywhere liquid and vapor are together in a system, like inside the evaporator and condenser coils, the pressure and temperature are locked together, so one tells you the other. On the job, the chart turns gauge readings into saturation temperatures: the suction pressure gives the temperature the evaporator is boiling at, and the liquid line pressure gives the temperature the condenser is condensing at. Compare those with your line temperatures and you have superheat and subcooling.

R-404A is a blend of R-125, R-143a and R-134a (safety class A1) made for commercial refrigeration, like walk-in coolers and freezers. It has a very high global warming potential (GWP), so it's being replaced by lower-GWP refrigerants in new equipment.

How it's calculated

Absolute pressure = gauge pressure + 14.696 psi (101.325 kPa, one standard atmosphere)
Saturation data: R-404A: CoolProp 8.0.0, R404A
Between table points (every 0.5 °C): ln(pressure) is interpolated linearly in 1 ÷ absolute temperature
Blends have separate liquid (bubble) and vapor (dew) curves
Glide = dew temperature − bubble temperature at the same pressure
Printed chart rows are solved by CoolProp at each exact temperature

Sources

If a number doesn't match your chart, email me what you entered and what you expected, and I'll check it against the source. You can also read how the numbers are checked.

Checked by Paul Williams · Updated October 31, 2026

Questions

What is the R-404A pressure at 40°F?

At 40°F, R-404A saturates at 85.4 psig on the vapor (dew) side and 86.9 psig on the liquid (bubble) side. At 100°F it's 234.7 psig vapor and 236.8 psig liquid.

Why are there two columns for R-404A?

R-404A is a blend of R-125, R-143a and R-134a (44/52/4 by weight) with about 1°F of glide, so its liquid and vapor pressures differ by 1 to 2 psi. Use the vapor column for superheat and the liquid column for subcooling.

How accurate is this chart?

It comes from NIST's equation of state for R-404A (Lemmon, 2003) through CoolProp. It matches Arkema's Forane 404A tables, which use NIST REFPROP, to within about 0.1 psi on every row from -40 to 150°F.

R-404A PT Chart