How to Calculate Your Blood-Alcohol Concentration (BAC) Level

1. Determine the number of drinks consumed using the following measurements:

1 drink = 12 oz Beer or
4 oz Wine or
1 oz Hard Liquor

2. In Table 1 (below), go to the number of drinks consumed at the top of the Table and then go down to the column containing your body weight. Write the number down: __________.

Table 1

Drinks ConsumedBody Weight	1	2	3	4	5	6	7	8	9	10
100 lb	.038	.075	.113	.150	.188	.225	.263	.300	.338	.375
120 lb	.031	.063	.094	.125	.156	.186	.219	.250	.281	.313
140 lb	.027	.53	.80	.107	.134	.161	.188	214	.241	.268
160 lb	.023	.047	.070	.094	.117	.141	.164	.188	.211	.234
180 lb	.021	.042	.063	.083	.104	.125	.146	.167	.188	.208
200 lb	.019	.038	.056	.075	.094	.113	.131	.150	.169	.188
220 lb	.017	.034	.051	.068	.085	.102	.119	.136	.153	.170
240 lb	.016	.031	.047	.063	.078	.094	.109	.125	.141	.156

3. In Table 2 (below), go to the number of hours since the first drink was consumed at the top of the Table and then go down to the column containing the Burn-off Rate. Write the number down: ____________.

Table 2

Hours Since 1st Drink	1	2	3	4	5	6
Burn-off Rate	.015	.030	.045	.060	.075	.090

4. Subtract the second number you wrote down (from #3.) from the first number you wrote down (from #2.) This is the estimated percentage of alcohol in your blood, or your “Blood-Alcohol Concentration (BAC) Level.”

5. Example: a person weighing 160 pounds who consumed 7 drinks = .164

The first drink was consumed 6 hours ago= .090

The estimated “Blood-Alcohol Concentration (BAC) level” = .074 (.164 - .090 = .074).

Disclaimer: This chart in intended for general informational purposes and cannot be relied upon to provide exact blood alcohol levels. Other factors may have a role in individual metabolism.