How to use this calculator
Enter each drink’s volume, strength and quantity. The simplified Widmark model assumes complete absorption of the entered alcohol and applies a constant illustrative elimination rate from the start of consumption. It does not simulate individual drink timing, food, delayed absorption, medications or personal metabolism. Historical body-water coefficients are rough group averages, not measurements of your physiology.
- Enter body weight units, body weight (kg), body-water model parameter and review the remaining options.
- Select Calculate or change a value to update the result. Read the result label and units before copying.
- Use Reset to restore the worked starting values.
Formula and method
This calculator provides only a rough educational estimate. It cannot determine whether you are safe or legally permitted to drive. If you have been drinking, do not drive. BAC can keep rising after the last drink. Modeled zero does not prove zero alcohol or no impairment. Coffee, cold showers, exercise and water do not reliably accelerate elimination. Seek emergency help for difficulty waking, seizures or slow or irregular breathing; do not wait for a calculation.
Worked example
Two 330 mL drinks at 5% ABV contain about 26 g of ethanol. At 70 kg with r = 0.68, the complete-absorption model before elimination is about 0.055%; after one modeled hour it is about 0.040%, displayed as approximately 0.04%. This is not a measured BAC.
Questions about blood alcohol content calculator
Can an estimated BAC tell me whether I can drive?
No. A calculated BAC is a rough model with substantial individual uncertainty. Neither a low value nor a modeled zero provides driving clearance. If you have been drinking, do not drive. The calculator deliberately provides no countdown to being sober, legal or safe.
What assumptions should I check?
This calculator provides only a rough educational estimate. It cannot determine whether you are safe or legally permitted to drive. If you have been drinking, do not drive. BAC can keep rising after the last drink. Modeled zero does not prove zero alcohol or no impairment. Coffee, cold showers, exercise and water do not reliably accelerate elimination. Seek emergency help for difficulty waking, seizures or slow or irregular breathing; do not wait for a calculation.
Are my inputs saved?
Calculations run in your browser. We store only tool IDs for favorites and recent tools. Sharing inputs in links is disabled for this category.
Health tools provide general estimates, not diagnoses or personal medical advice. BMI offers a labeled CDC child/teen reference; adult screening bands must not be applied to children. Discuss health and exercise decisions with a qualified professional. Read the tool-specific sources below for background on the method.