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HEALTH

BAC Calculator

Estimate estimated bac from standard, body weight, hours elapsed with the BAC Calculator.

Choose alcohol inputUse standard drinks or enter beer, wine, liquor, and another beverage.
2 options
ESTIMATED BAC0.052%

Widmark estimate from 42.0 g alcohol. Any alcohol can impair driving; do not drive or use this estimate to decide whether to drive. Educational estimate only; not medical advice.

Pure alcohol
42.0 g
Estimated time to zero
3.5 hours
Estimate based on the values shown
MethodWidmark estimate from ethanol grams, body weight, sex distribution factor, and elapsed time.

Before you use the result

Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional.

Sources

EDITORIAL NOTES

Using the BAC Calculator responsibly

Page-specific guidance based on this calculator’s implemented method, inputs, and known limits.

What this result is useful for

The BAC calculator illustrates a Widmark-style population estimate from alcohol amount, body weight, sex distribution factor, and elapsed time. It is included for education about uncertainty and impairment, not to decide whether it is safe or legal to drive.

Assumptions and limits

Absorption and elimination vary with beverage strength, pour size, food, time, medications, health, and individual physiology. The estimate cannot measure current impairment and may be materially wrong. Legal limits also vary by place, age, licence, and activity.

How to check the result

Verify beverage volumes and alcohol percentages, and treat every result as uncertain. Do not drive, operate machinery, supervise safety-critical work, or delay emergency help based on this output. Only an appropriate breath or blood test can measure alcohol concentration at a point in time.

Content review: August 30, 2026
CALCULATOR GUIDE

How to use the BAC Calculator

Estimate estimated bac from standard, body weight, hours elapsed with the BAC Calculator. It includes Standard drinks, Blood Alcohol Concentration (BAC) workflows, so choose the one that matches the values you actually know. Use it to understand an educational estimate and the inputs behind it, not as a diagnosis or treatment decision.

Step by step

  1. For the BAC example, select Standard drinks and enter standard, body weight, hours elapsed, gender. Keep each value in the unit displayed beside its field.
  2. Review the selected BAC workflow and inputs, then read estimated bac in the result panel.
  3. Change one BAC assumption at a time to compare scenarios. Use Reset to restore this tool's worked example values.

How the calculation works

Widmark estimate from ethanol grams, body weight, sex distribution factor, and elapsed time.

Worked example

To reproduce the BAC worked example, reset the calculator. Select the Standard drinks workflow. Use standard 3 drinks; body weight 75 kg; hours elapsed 2 hours; gender Male. The result is estimated bac of 0.052%. Widmark estimate from 42.0 g alcohol. Review the displayed units before comparing the result.

Understanding the result

The BAC reports estimated bac. Use it to understand an educational estimate and the inputs behind it, not as a diagnosis or treatment decision. Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional.

How to check the answer

Check the BAC estimate by confirming the units and supported ranges for standard, body weight, hours elapsed. Compare estimated bac with another published method or direct measurement when available, and ask a clinician before using it for a health decision.

Common questions

What does the BAC calculate?

Estimate estimated bac from standard, body weight, hours elapsed with the BAC Calculator.

Which inputs does the BAC example use?

The worked example uses standard, body weight, hours elapsed, gender in the Standard drinks workflow. Other workflows can show different fields. Keep the chosen workflow and units with the result when comparing calculations.

Is the BAC result exact?

Educational estimate only; it cannot diagnose a condition or replace advice from a qualified health professional. Recheck standard, body weight, hours elapsed and use estimated bac only for a decision where that level of precision is appropriate.

Formula tests, limits, and sources reviewed September 1, 2026. Guide examples updated October 12, 2026.
INTERPRET THE RESULTRead the health guideCheck assumptions, limitations and comparison methods →
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