Calculation Of Estimated Blood Alcohol Concentration (BAC)
Body Weight: Calculations are for people with a normal body weight for their height, free of drugs or other affecting medication and neither unusually thin nor obese.
Drink Equivalents: 1 drink equals:
1 ½oz rum, rye, scotch, brandy, gin, vodka, etc.
1 12-oz. bottle normal-strength beer
3 oz fortified wine
5 oz table wine
Using the Chart: Find the appropriate figure using the proper chart (male or female), body weight, and number of drinks consumed.
Then subtract the time factor (see Time Factor Table Below) from the figure on the chart to obtain the approximate BAC. For example, for a 150-lb. man who has had 4 drinks in two hours, take the figure .116 (from the chart for males) and subtract .030 (from the Time Factor Table) to obtain a BAC of .086%
Time Factor Table
Hours Since 1st Drink
Subtract from BAC
1
.015
2
.030
3
.045
4
.060
5
.075
6
.090
NUMBER OF DRINKS: MALES
Ideal body
wt. (lbs.)
1
2
3
4
5
6
7
8
9
10
100
.043
.087
.130
.174
.217
.261
.304
.348
.391
.435
125
.034
.069
.103
.139
.173
.209
.242
.278
.312
.346
150
.029
.058
.087
.116
.145
.174
.203
.232
.261
.290
175
.025
.050
.075
.100
.125
.150
.175
.200
.225
.250
200
.022
.043
.065
.087
.108
.130
.152
.174
.195
.217
225
.019
.039
.058
.078
.097
.117
.136
.156
.175
.195
250
.017
.035
.052
.070
.087
.105
.122
.139
.156
.173
NUMBER OF DRINKS: FEMALES
Ideal body weight (lbs.)
1
2
3
4
5
6
7
8
9
10
100
.050
.101
.152
.203
.253
.304
.355
.406
.456
.507
125
.040
.080
.120
.162
.202
.244
.282
.324
.364
.404
150
.034
.068
.101
.135
.169
.203
.237
.271
.304
.338
175
.029
.058
.087
.117
.146
.175
.204
.233
.262
.292
200
.026
.050
.076
.101
.126
.152
.177
.203
.227
.253
225
.022
.045
.068
.091
.113
.136
.159
.182
.204
.227
250
.020
.041
.061
.082
.101
.122
.142
.162
.182
.202
From The Encyclopedia of alcoholism by Glen Evans and Robert O'Brien. Copyright 1991 by Facts On File and Greenspring, Inc. Reprinted with permission of Facts on File Inc., New York.