Target Superheat Calculator

Enter the outdoor temperature at the condenser and the return air wet bulb to get the target superheat for a fixed orifice or piston system. It reads California Title 24's charging table, and checks your measured superheat against it. The whole table is below, ready to print.

Full table ↓

Title 24 target superheat table

Target superheat in °F for a fixed orifice or piston system, from Table RA3.2-2. Find the outdoor dry bulb at the condenser down the left, then the return air wet bulb across the top. A dash means the target is below 5°F, so the charge can't be checked by superheat in those conditions.

Target superheat in °F by outdoor dry bulb (rows, °F) and return air wet bulb (columns, °F). A dash means no valid target.
Wet bulb →Outdoor ↓	50	51	52	53	54	55	56	57	58	59	60	61	62	63	64	65	66	67	68	69	70	71	72	73	74	75	76
55	8.8	10.1	11.5	12.8	14.2	15.6	17.1	18.5	20.0	21.5	23.1	24.6	26.2	27.8	29.4	31.0	32.4	33.8	35.1	36.4	37.7	39.0	40.2	41.5	42.7	43.9	45.0
56	8.6	9.9	11.2	12.6	14.0	15.4	16.8	18.2	19.7	21.2	22.7	24.2	25.7	27.3	28.9	30.5	31.8	33.2	34.6	35.9	37.2	38.5	39.7	41.0	42.2	43.4	44.6
57	8.3	9.6	11.0	12.3	13.7	15.1	16.5	17.9	19.4	20.8	22.3	23.8	25.3	26.8	28.3	29.9	31.3	32.6	34.0	35.3	36.7	38.0	39.2	40.5	41.7	43.0	44.2
58	7.9	9.3	10.6	12.0	13.4	14.8	16.2	17.6	19.0	20.4	21.9	23.3	24.8	26.3	27.8	29.3	30.7	32.1	33.5	34.8	36.1	37.5	38.7	40.0	41.3	42.5	43.7
59	7.5	8.9	10.2	11.6	13.0	14.4	15.8	17.2	18.6	20.0	21.4	22.9	24.3	25.7	27.2	28.7	30.1	31.5	32.9	34.3	35.6	36.9	38.3	39.5	40.8	42.1	43.3
60	7.0	8.4	9.8	11.2	12.6	14.0	15.4	16.8	18.2	19.6	21.0	22.4	23.8	25.2	26.6	28.1	29.6	31.0	32.4	33.7	35.1	36.4	37.8	39.1	40.4	41.6	42.9
61	6.5	7.9	9.3	10.7	12.1	13.5	14.9	16.3	17.7	19.1	20.5	21.9	23.3	24.7	26.1	27.5	29.0	30.4	31.8	33.2	34.6	35.9	37.3	38.6	39.9	41.2	42.4
62	6.0	7.4	8.8	10.2	11.7	13.1	14.5	15.9	17.3	18.7	20.1	21.4	22.8	24.2	25.5	27.0	28.4	29.9	31.3	32.7	34.1	35.4	36.8	38.1	39.4	40.7	42.0
63	5.3	6.8	8.3	9.7	11.1	12.6	14.0	15.4	16.8	18.2	19.6	20.9	22.3	23.6	25.0	26.4	27.8	29.3	30.7	32.2	33.6	34.9	36.3	37.7	39.0	40.3	41.6
64	–	6.1	7.6	9.1	10.6	12.0	13.5	14.9	16.3	17.7	19.0	20.4	21.7	23.1	24.4	25.8	27.3	28.7	30.2	31.6	33.0	34.4	35.8	37.2	38.5	39.9	41.2
65	–	5.4	7.0	8.5	10.0	11.5	12.9	14.3	15.8	17.1	18.5	19.9	21.2	22.5	23.8	25.2	26.7	28.2	29.7	31.1	32.5	33.9	35.3	36.7	38.1	39.4	40.8
66	–	–	6.3	7.8	9.3	10.8	12.3	13.8	15.2	16.6	18.0	19.3	20.7	22.0	23.2	24.6	26.1	27.6	29.1	30.6	32.0	33.4	34.9	36.3	37.6	39.0	40.4
67	–	–	5.5	7.1	8.7	10.2	11.7	13.2	14.6	16.0	17.4	18.8	20.1	21.4	22.7	24.1	25.6	27.1	28.6	30.1	31.5	33.0	34.4	35.8	37.2	38.6	39.9
68	–	–	–	6.3	8.0	9.5	11.1	12.6	14.0	15.5	16.8	18.2	19.5	20.8	22.1	23.5	25.0	26.5	28.0	29.5	31.0	32.5	33.9	35.3	36.8	38.1	39.5
69	–	–	–	5.5	7.2	8.8	10.4	11.9	13.4	14.8	16.3	17.6	19.0	20.3	21.5	22.9	24.4	26.0	27.5	29.0	30.5	32.0	33.4	34.9	36.3	37.7	39.1
70	–	–	–	–	6.4	8.1	9.7	11.2	12.7	14.2	15.7	17.0	18.4	19.7	20.9	22.3	23.9	25.4	27.0	28.5	30.0	31.5	33.0	34.4	35.9	37.3	38.7
71	–	–	–	–	5.6	7.3	8.9	10.5	12.1	13.6	15.0	16.4	17.8	19.1	20.3	21.7	23.3	24.9	26.4	28.0	29.5	31.0	32.5	34.0	35.4	36.9	38.3
72	–	–	–	–	–	6.4	8.1	9.8	11.4	12.9	14.4	15.8	17.2	18.5	19.7	21.2	22.8	24.3	25.9	27.4	29.0	30.5	32.0	33.5	35.0	36.5	37.9
73	–	–	–	–	–	5.6	7.3	9.0	10.7	12.2	13.7	15.2	16.6	17.9	19.2	20.6	22.2	23.8	25.4	26.9	28.5	30.0	31.5	33.1	34.6	36.0	37.5
74	–	–	–	–	–	–	6.5	8.2	9.9	11.5	13.1	14.5	15.9	17.3	18.6	20.0	21.6	23.2	24.8	26.4	28.0	29.5	31.1	32.6	34.1	35.6	37.1
75	–	–	–	–	–	–	5.6	7.4	9.2	10.8	12.4	13.9	15.3	16.7	18.0	19.4	21.1	22.7	24.3	25.9	27.5	29.1	30.6	32.2	33.7	35.2	36.7
76	–	–	–	–	–	–	–	6.6	8.4	10.1	11.7	13.2	14.7	16.1	17.4	18.9	20.5	22.1	23.8	25.4	27.0	28.6	30.1	31.7	33.3	34.8	36.3
77	–	–	–	–	–	–	–	5.7	7.5	9.3	11.0	12.5	14.0	15.4	16.8	18.3	20.0	21.6	23.2	24.9	26.5	28.1	29.7	31.3	32.8	34.4	36.0
78	–	–	–	–	–	–	–	–	6.7	8.5	10.2	11.8	13.4	14.8	16.2	17.7	19.4	21.1	22.7	24.4	26.0	27.6	29.2	30.8	32.4	34.0	35.6
79	–	–	–	–	–	–	–	–	5.9	7.7	9.5	11.1	12.7	14.2	15.6	17.1	18.8	20.5	22.2	23.8	25.5	27.1	28.8	30.4	32.0	33.6	35.2
80	–	–	–	–	–	–	–	–	–	6.9	8.7	10.4	12.0	13.5	15.0	16.6	18.3	20.0	21.7	23.3	25.0	26.7	28.3	29.9	31.6	33.2	34.8
81	–	–	–	–	–	–	–	–	–	6.0	7.9	9.7	11.3	12.9	14.3	16.0	17.7	19.4	21.1	22.8	24.5	26.2	27.9	29.5	31.2	32.8	34.4
82	–	–	–	–	–	–	–	–	–	5.2	7.1	8.9	10.6	12.2	13.7	15.4	17.2	18.9	20.6	22.3	24.0	25.7	27.4	29.1	30.7	32.4	34.0
83	–	–	–	–	–	–	–	–	–	–	6.3	8.2	9.9	11.6	13.1	14.9	16.6	18.4	20.1	21.8	23.5	25.2	26.9	28.6	30.3	32.0	33.7
84	–	–	–	–	–	–	–	–	–	–	5.5	7.4	9.2	10.9	12.5	14.3	16.1	17.8	19.6	21.3	23.0	24.8	26.5	28.2	29.9	31.6	33.3
85	–	–	–	–	–	–	–	–	–	–	–	6.6	8.5	10.3	11.9	13.7	15.5	17.3	19.0	20.8	22.6	24.3	26.0	27.8	29.5	31.2	32.9
86	–	–	–	–	–	–	–	–	–	–	–	5.8	7.8	9.6	11.3	13.2	15.0	16.7	18.5	20.3	22.1	23.8	25.6	27.3	29.1	30.8	32.6
87	–	–	–	–	–	–	–	–	–	–	–	5.0	7.0	8.9	10.6	12.6	14.4	16.2	18.0	19.8	21.6	23.4	25.1	26.9	28.7	30.4	32.2
88	–	–	–	–	–	–	–	–	–	–	–	–	6.3	8.2	10.0	12.0	13.9	15.7	17.5	19.3	21.1	22.9	24.7	26.5	28.3	30.1	31.8
89	–	–	–	–	–	–	–	–	–	–	–	–	5.5	7.5	9.4	11.5	13.3	15.1	17.0	18.8	20.6	22.4	24.3	26.1	27.9	29.7	31.5
90	–	–	–	–	–	–	–	–	–	–	–	–	–	6.8	8.8	10.9	12.8	14.6	16.5	18.3	20.1	22.0	23.8	25.6	27.5	29.3	31.1
91	–	–	–	–	–	–	–	–	–	–	–	–	–	6.1	8.1	10.3	12.2	14.1	15.9	17.8	19.7	21.5	23.4	25.2	27.1	28.9	30.8
92	–	–	–	–	–	–	–	–	–	–	–	–	–	5.4	7.5	9.8	11.7	13.5	15.4	17.3	19.2	21.1	22.9	24.8	26.7	28.5	30.4
93	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.8	9.2	11.1	13.0	14.9	16.8	18.7	20.6	22.5	24.4	26.3	28.2	30.1
94	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.2	8.7	10.6	12.5	14.4	16.3	18.2	20.2	22.1	24.0	25.9	27.8	29.7
95	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.6	8.1	10.0	12.0	13.9	15.8	17.8	19.7	21.6	23.6	25.5	27.4	29.4
96	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	7.5	9.5	11.4	13.4	15.3	17.3	19.2	21.2	23.2	25.1	27.1	29.0
97	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	7.0	8.9	10.9	12.9	14.9	16.8	18.8	20.8	22.7	24.7	26.7	28.7
98	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.4	8.4	10.4	12.4	14.4	16.4	18.3	20.3	22.3	24.3	26.3	28.3
99	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.8	7.9	9.9	11.9	13.9	15.9	17.9	19.9	21.9	24.0	26.0	28.0
100	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.3	7.3	9.3	11.4	13.4	15.4	17.5	19.5	21.5	23.6	25.6	27.7
101	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.8	8.8	10.9	12.9	15.0	17.0	19.1	21.1	23.2	25.3	27.3
102	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.2	8.3	10.4	12.4	14.5	16.6	18.6	20.7	22.8	24.9	27.0
103	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.7	7.8	9.9	11.9	14.0	16.1	18.2	20.3	22.4	24.5	26.7
104	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.2	7.2	9.3	11.5	13.6	15.7	17.8	19.9	22.1	24.2	26.3
105	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.7	8.8	11.0	13.1	15.2	17.4	19.5	21.7	23.8	26.0
106	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.2	8.3	10.5	12.6	14.8	17.0	19.1	21.3	23.5	25.7
107	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.7	7.9	10.0	12.2	14.4	16.6	18.7	21.0	23.2	25.4
108	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.2	7.4	9.5	11.7	13.9	16.1	18.4	20.6	22.8	25.1
109	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.9	9.1	11.3	13.5	15.7	18.0	20.2	22.5	24.7
110	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.4	8.6	10.8	13.1	15.3	17.6	19.9	22.1	24.4
111	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.9	8.1	10.4	12.6	14.9	17.2	19.5	21.8	24.1
112	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	5.4	7.6	9.9	12.2	14.5	16.8	19.1	21.5	23.8
113	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	7.2	9.5	11.8	14.1	16.4	18.8	21.1	23.5
114	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.7	9.0	11.4	13.7	16.1	18.4	20.8	23.2
115	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	6.2	8.6	10.9	13.3	15.7	18.1	20.5	22.9

From pockethvac.com/target-superheat-calculator/. 2025 Reference Appendices for the Building Energy Efficiency Standards (CEC-400-2025-010-AP), Table RA3.2-2 Target Superheat.

What is target superheat?

Target superheat is the superheat a fixed orifice or piston system should have when its charge is right, under the conditions it's running in right now. A fixed metering device can't adjust to the load, so the right superheat changes with it: hot outdoor air and a low indoor wet bulb call for less superheat, and mild outdoor air and a high indoor wet bulb call for more.

The target comes from a charging table that uses two readings: the indoor wet bulb at the return and the outdoor dry bulb at the condenser. Measure the actual superheat and compare. If it's well above the target the system usually needs refrigerant, and if it's well below, it usually has too much.

How it's calculated

Target superheat = Title 24 Table RA3.2-2 at (outdoor dry bulb, return wet bulb), each rounded to the nearest whole °F
Measured − target, installer tolerance ±5°F (ECC-Rater ±8°F)
Above target: add refrigerant. Below target: remove refrigerant
In °C: inputs convert to °F for the lookup, and the target converts back as a difference (× 5/9)

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

Which systems use a target superheat?

Systems with a fixed metering device: a piston or fixed orifice. On a TXV or EEV system the valve holds superheat steady, so the charge is checked by subcooling against the manufacturer's target (on the nameplate or in the installation manual) instead.

Where does the target come from?

California Title 24's Table RA3.2-2, which has been the same in every edition from 2008 to 2025. At 95°F outdoors and a 66°F return wet bulb the target is 10.0°F. Carrier's superheat charging table agrees with it within 1°F everywhere the two overlap. If the manufacturer gives its own chart, use that.

Why does it sometimes say the test can't be done?

Where the table shows a dash, the target superheat is below 5°F, usually because it's hot outside and too cool inside. Title 24 says the charge can't be verified by superheat then. A badly undercharged unit still shows over 9°F of superheat, but an overcharge won't show. Warm the house up or come back another time.

What are the other conditions for the test?

Title 24 requires 55 to 115°F outdoors, return air at 70°F or warmer, return wet bulb at 76°F or lower, and at least 15 minutes of running. The airflow across the coil has to be verified first (350 CFM per ton for new systems, 300 for altered ones). Below 55°F outdoors, weigh in the charge.