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Air Home > Air Quality Forecast > AQI Conversion - PM
AQI CONVERSION TABLE
Table for Converting 24-Hour Averaged Particle Pollution Concentrations
in Micrograms per cubic meter (µg/m 3 ) to the Air Quality Index (AQI)
GOOD
MODERATE
UNHEAL. FOR SEN.
UNHEALTHY
UNHEALTHY
VERY UNHEALTHY
ILO =  
0
ILO =  
51
ILO =  
101
ILO =  
151
ILO =  
151
ILO =  
201
IHI =
50
IHI =
100
IHI =
150
IHI =
200
IHI =
200
IHI =
300
BPLO =
0
BPLO =
15.5
BPLO =
35.5
BPLO =
55.5
BPLO =
55.5
BPLO =
140.5
BPHI =
15.4
BPHI =
35.4
BPHI =
55.4
BPHI =
140.4
BPHI =
140.4
BPHI =
210.4
PM Conc.
AQI
PM Conc.
AQI
PM Conc.
AQI
PM Conc.
AQI
PM Conc.
AQI
PM Conc.
AQI
0.4
1
15.5
51
35.5
101
55.5
151
99.6
176
140.5
201
0.6
2
15.9
52
35.9
102
57.2
152
101.3
177
141.5
202
1.0
3
16.3
53
36.3
103
58.9
153
103.0
178
142.5
204
1.2
4
16.7
54
36.7
104
60.6
154
104.7
179
143.5
205
1.6
5
17.1
55
37.1
105
62.3
155
106.4
180
144.5
207
2.0
6
17.5
56
37.5
106
64.0
156
108.1
181
145.5
208
2.2
7
17.9
57
37.9
107
65.7
157
109.8
182
146.5
209
2.6
8
18.3
58
38.3
108
67.4
158
111.5
183
147.5
211
2.8
9
18.7
59
38.7
109
69.1
159
113.2
184
148.5
212
3.2
10
19.1
60
39.1
110
70.8
160
114.9
185
149.5
214
3.4
11
19.5
61
39.5
111
72.5
161
116.6
186
150.5
215
3.8
12
19.9
62
39.9
112
74.2
162
118.3
187
151.5
217
4.0
13
20.3
63
40.3
113
75.9
163
120.0
188
152.5
218
4.4
14
20.7
64
40.7
114
77.6
164
121.7
189
153.5
219
4.6
15
21.1
65
41.1
115
79.3
165
123.4
190
154.5
221
5.0
16
21.5
66
41.5
116
81.0
166
125.1
191
155.5
222
5.2
17
22.2
67
41.9
117
82.7
167
126.8
192
156.5
224
5.6
18
22.6
68
42.3
118
84.4
168
128.5
193
157.5
225
6.0
19
23.0
69
42.7
119
86.1
169
130.2
194
158.5
226
6.2
20
23.4
70
43.1
120
87.8
170
131.9
195
159.5
228
6.6
21
23.8
71
43.5
121
89.5
171
133.6
196
160.5
229
6.8
22
24.2
72
43.9
122
91.2
172
135.3
197
161.5
231
7.2
23
24.6
73
44.3
123
92.9
173
137.0
198
162.5
232
7.4
24
25.0
74
44.7
124
94.6
174
138.7
199
163.5
234
7.8
25
25.4
75
45.1
125
96.3
175
140.4
200
164.5
235
8.0
26
25.8
76
45.5
126
8.4
27
26.2
77
45.9
127
AQI Conversion Formula
8.6
28
26.6
78
46.3
128
   
9.0
29
27.0
79
46.7
129
  IHI - ILO    
9.2
30
27.4
80
47.1
130
AQI =    ------------------------   X   (CPM - BPLO) + ILO
9.6
31
27.8
81
47.5
131
  BPHI - BPLO  
10.0
32
28.2
82
47.9
132
   
10.2
33
28.6
83
48.3
133
AQI = Air Quality Index  
10.6
34
29.0
84
48.7
134
ILO = Index Value at the Lower Limit of the AQI Category  
10.8
35
29.4
85
49.4
135
IHI = Index Value at the Upper Limit of the AQI Category
11.2
36
29.8
86
49.8
136
BPLO = Break Point Conc. at the Lower Limit of the AQI Categ
11.4
37
30.2
87
50.2
137
BPHI = Break Point Conc. at the Upper Limit of the AQI Catego
11.8
38
30.6
88
50.6
138
CPM = 24 -Hour Particle pollution Concentration  
12.0
39
31.0
89
51.0
139
12.4
40
31.4
90
51.4
140
12.6
41
31.8
91
51.8
141
13.0
42
32.2
92
52.2
142
13.2
43
32.6
93
52.6
143
13.6
44
33.0
94
53.0
144
14.0
45
33.4
95
53.4
145
14.2
46
33.8
96
53.8
146
14.6
47
34.2
97
54.2
147
14.8
48
34.6
98
54.6
148
15.2
49
35.0
99
55.0
149
15.4
50
35.4
100
55.4
150