Plano DWI Lawyer Blog

To estimate you BAC, do the following:
1. Total the number of drinks*;
2. Then use the chart below to find the number of “drinks” in the top row and the “body weight” in the left column. Where the correct column and row meet is the estimated percent of your BAC:
1 2 3 4 5 6 7 8 9 10 11 12
100 lb .038 .075 .113 .150 .188 .225 .263 .300 .338 .375 .413 .450
110 lb .034 .066 .103 .137 .172 .207 .241 .275 .309 .344 .379 .412
120 lb .031 .063 .094 .125 .156 .188 .219 .250 .281 .313 .344 .375
130 lb .029 .058 .087 .116 .145 .174 .203 .232 .261 .290 .320 .348
140 lb .027 .054 .080 .107 .134 .161 .188 .214 .241 .268 .295 .321
150 lb .025 .050 .075 .100 .125. .151 .176 .201 .226 .251 .276 .301
160 lb .023 .047 .070 .094 .117 .141 .164 .188 .211 .234 .258 .281
170 lb .022 .045 .066 .088 .110 .132 .155 .178 .200 .221 .244 .265
180 lb .021 .042 .063 .083 .104 .125 .146 .167 .188 .208 .229 .250
190 lb .020 .040 .059 .079 .099 .119 .138 .158 .179 .198 .217 .237
200 lb .019 .038 .056 .075 .094 .113 .131 .150 .169 .188 .206 .225
210 lb .018 .036 .053 .071 .090 .107 .125 .143 .161 .179 .197 .215
220 lb .017 .034 .051 .068 .085 .102 .119 .136 .153 .170 .188 .205
230 lb .016 .032 .049 .065 .081 .098 .115 .130 .147 .163 .180 .196
240 lb .016 .031 .047 .047 .078 .094 .109 .125 .141 .156 .172 .188

The last step in determining your estimated BAC is to account for the amount of alcohol your body will metabolize over a period of time. Your body will metabolize, or get rid of, a percentage of alcohol over time. The chart above assumes that all of your drinks were in one (1) hour. If you had you drinks in a time frame longer than one (1) hour then you need the following calculation to account for the amount of alcohol your body has metabolized.
• Find your estimated BAC from the chart above using your weight and the number of drinks;
• Then subtract from this number the percent of alcohol metabolized or “burned up” during the time since your first drink. This number is .015% per hour.
• Example: A 180 lb man has 8 drinks in 4 hours:
o BAC from chart above: .167
o .015 x 4=.060
o BAC= .167 -.060= .107%

*1 “drink” equals”
• 1 ounce of 100-proof liquor; or
• one five ounce glass of wine; or
• one 12-ounce bottle of beer.