As a general rule, there are 7 grams of protein per 1oz of cooked meat.
It's impossible to give you an answer because each chicken breast is a different size and will contain a different amount of protein. An average sized chicken breast is around 6oz and will have around 45g of protein.
Your best bet is to weigh the chicken breast and calculate the nutrition facts specifically.
Below is the nutrition data for 100g of cooked chicken
[TABLE="class: tableizer-table, width: 698"]
[TR]
[TD]Nutrient[/TD]
[TD="width: 60, align: center"]
Skinless, boneless breast
[/TD]
[TD="width: 63, align: center"]
Skin-on, bone-in breast
[/TD]
[TD="width: 80, align: center"]
Drumstick, skinless
[/TD]
[TD="width: 68, align: center"]
Drumstick, skin-on
[/TD]
[TD="width: 54, align: center"]
Thigh, skinless
[/TD]
[TD="width: 63, align: center"]
Thigh, skin-on
[/TD]
[TD="width: 50, align: center"]
Wing, skin-on
[/TD]
[TD="width: 73, align: center"]
Wing, without skin
[/TD]
[TD="width: 68, align: center"]
Whole Chicken, meat only
[/TD]
[TD="width: 83, align: center"]
Whole Chicken, meat and skin
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Calories[/TD]
[TD="width: 60, align: center"]
165
[/TD]
[TD="width: 63, align: center"]
197
[/TD]
[TD="width: 80, align: center"]
175
[/TD]
[TD="width: 68, align: center"]
216
[/TD]
[TD="width: 54, align: center"]
209
[/TD]
[TD="width: 63, align: center"]
229
[/TD]
[TD="width: 50, align: center"]
290
[/TD]
[TD="width: 73, align: center"]
203
[/TD]
[TD="width: 68, align: center"]
167
[/TD]
[TD="width: 83, align: center"]
239
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Protein (grams)[/TD]
[TD="width: 60, align: center"]
31
[/TD]
[TD="width: 63, align: center"]
30
[/TD]
[TD="width: 80, align: center"]
28
[/TD]
[TD="width: 68, align: center"]
27
[/TD]
[TD="width: 54, align: center"]
26
[/TD]
[TD="width: 63, align: center"]
25
[/TD]
[TD="width: 50, align: center"]
27
[/TD]
[TD="width: 73, align: center"]
30
[/TD]
[TD="width: 68, align: center"]
25
[/TD]
[TD="width: 83, align: center"]
24
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Total fat (grams)[/TD]
[TD="width: 60, align: center"]
3.6
[/TD]
[TD="width: 63, align: center"]
7.8
[/TD]
[TD="width: 80, align: center"]
5.7
[/TD]
[TD="width: 68, align: center"]
11.2
[/TD]
[TD="width: 54, align: center"]
10.9
[/TD]
[TD="width: 63, align: center"]
15.5
[/TD]
[TD="width: 50, align: center"]
19.5
[/TD]
[TD="width: 73, align: center"]
8.1
[/TD]
[TD="width: 68, align: center"]
6.6
[/TD]
[TD="width: 83, align: center"]
13.4
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Saturated fat (grams)[/TD]
[TD="width: 60, align: center"]
1
[/TD]
[TD="width: 63, align: center"]
2.2
[/TD]
[TD="width: 80, align: center"]
1.5
[/TD]
[TD="width: 68, align: center"]
3
[/TD]
[TD="width: 54, align: center"]
3
[/TD]
[TD="width: 63, align: center"]
4.3
[/TD]
[TD="width: 50, align: center"]
5.4
[/TD]
[TD="width: 73, align: center"]
2.3
[/TD]
[TD="width: 68, align: center"]
1.8
[/TD]
[TD="width: 83, align: center"]
3.7
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Monounsaturated fat (grams)[/TD]
[TD="width: 60, align: center"]
1.2
[/TD]
[TD="width: 63, align: center"]
3
[/TD]
[TD="width: 80, align: center"]
1.9
[/TD]
[TD="width: 68, align: center"]
4.2
[/TD]
[TD="width: 54, align: center"]
4.1
[/TD]
[TD="width: 63, align: center"]
6.1
[/TD]
[TD="width: 50, align: center"]
7.6
[/TD]
[TD="width: 73, align: center"]
2.6
[/TD]
[TD="width: 68, align: center"]
2.5
[/TD]
[TD="width: 83, align: center"]
5.4
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Polyunsaturated fat (grams)[/TD]
[TD="width: 60, align: center"]
0.7
[/TD]
[TD="width: 63, align: center"]
1.7
[/TD]
[TD="width: 80, align: center"]
1.4
[/TD]
[TD="width: 68, align: center"]
2.5
[/TD]
[TD="width: 54, align: center"]
2.5
[/TD]
[TD="width: 63, align: center"]
3.4
[/TD]
[TD="width: 50, align: center"]
4.1
[/TD]
[TD="width: 73, align: center"]
1.8
[/TD]
[TD="width: 68, align: center"]
1.5
[/TD]
[TD="width: 83, align: center"]
2.9
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Cholesterol (milligrams)[/TD]
[TD="width: 60, align: center"]
85
[/TD]
[TD="width: 63, align: center"]
84
[/TD]
[TD="width: 80, align: center"]
93
[/TD]
[TD="width: 68, align: center"]
91
[/TD]
[TD="width: 54, align: center"]
95
[/TD]
[TD="width: 63, align: center"]
93
[/TD]
[TD="width: 50, align: center"]
84
[/TD]
[TD="width: 73, align: center"]
85
[/TD]
[TD="width: 68, align: center"]
75
[/TD]
[TD="width: 83, align: center"]
76
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"]Sodium (milligrams)[/TD]
[TD="width: 60, align: center"]
74
[/TD]
[TD="width: 63, align: center"]
71
[/TD]
[TD="width: 80, align: center"]
95
[/TD]
[TD="width: 68, align: center"]
90
[/TD]
[TD="width: 54, align: center"]
88
[/TD]
[TD="width: 63, align: center"]
84
[/TD]
[TD="width: 50, align: center"]
82
[/TD]
[TD="width: 73, align: center"]
92
[/TD]
[TD="width: 68, align: center"]
75
[/TD]
[TD="width: 83, align: center"]
73
[/TD]
[/TR]
[TR]
[TD="width: 208, align: center"][/TD]
[TD="width: 60, align: center"][/TD]
[/TR]
[/TABLE]