Tennessee BAC Limits

The Tennessee blood alcohol content level, or BAC, is set at different levels based upon a driver’s age, and if a driver holds a commercial driver’s license (CDL). The Tennessee BAC for non-commercial drivers over 21 years of age is 0.08%. The BAC for drivers under 21 years of age is 0.02%, and the BAC for commercial CDL drivers is 0.04%.

Your BAC is a measure of how much alcohol is in your system at the time the police ask you to blow into a portable breathalyzer, or breath machine. The breath test machine measures the percent of alcohol in your bloodstream, and it will display the results almost immediately. Tennessee DUI breath tests are used at almost every Tennessee DUI roadblock. These devices are a quick way for police to determine if you are going to be arrested for drunk driving.

Tennessee Field Sobriety Tests

The other major tests you will be given are field sobriety tests, where an officer asks you to walk and turn, follow the officer’s finger movements back and forth, and the one-leg stand. These field sobriety tests are voluntary! You can refuse to take them. Even if you are 100% sober, you can still fail these tests because unusual agility and coordination are required.

The below BAC chart will tell you your approximate BAC level based on your weight, the number of drinks you had, and how long ago you took your last drink before driving. All BAC levels are estimates based on average biological statistics, and you should never drink and drive.

Depending on the circumstances of your DUI arrest, you may be booked for DUI even if your BAC is less than the legal Tennessee BAC limit.

 

# of Drinks Consumed

Body Weight 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 .063 .078 .094 .109 .125 .141 .156 .172 .188

Can I refuse to take a DUI breath test or blood test in Tennessee?

Tennessee has a DUI implied consent law, which means that when you were issued your Tennessee driver’s license, you automatically gave your implied consent to submit to a DUI chemical test.  If you refuse to take a breath test or blood test, you will be subject to a fine and an automatic license suspension.