Existing incandescent light bulb size
25
40
50
60
75
100
150
watts
Replacement ENERGY STAR® compact fluorescent bulb size
9
13
15
20
23
34
50
watts
Number of light bulbs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
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
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
bulbs
Hours of use per day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
hours
Cost per incandescent light bulb
0
1
2
3
4
5
6
7
8
9
10
.
00
25
50
75
dollars
Cost per ENERGY STAR® compact fluorescent bulb
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
.
00
25
50
75
dollars
Electricity cost
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
.
0
1
2
3
4
5
6
7
8
9
cents per KWH
Calculator provided courtesy of the sponsoring
organizations of
Public
Utilities Commission