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BAC Calculator

Estimate your blood alcohol content

Impaired

4.041%

Legal Limit (USA)

0.080%

Time Until Sober

2h 42m

Disclaimer

This calculator provides estimates only. Actual BAC varies based on many factors. Never drink and drive. When in doubt, use a rideshare or designated driver.

Blood Alcohol Content

4.041%

Impaired

Legal Limit

0.080%

USA

Until Sober

2h 42m

estimate

BAC vs. Legal Limit

0.000%0.080% limit0.200%
Sober (0.00-0.03%)
Impaired (0.04-0.07%)
Legally Drunk (0.08-0.14%)
Dangerous (0.15%+)

Effects at this level

  • Reduced coordination
  • Slower reaction time
  • Impaired judgment
  • DO NOT DRIVE

Example Calculations

13 Beers, 180 lb Male, 2 Hours

Inputs

Drinks3 beers
Weight180 lbs
GenderMale
Hours Elapsed2

Result

Estimated BAC4.041%
StatusImpaired
Time Until Sober2h 42m

Alcohol = 3 x 0.6 oz = 1.8 oz. BAC = (1.8 x 5.14) / (180 x 0.73) - (0.015 x 2) = 9.252 / 131.4 - 0.03 = 0.0704 - 0.03 = 0.0404. Displayed as (0.0404 x 100).toFixed(3) = 4.041%. Time until sober = 0.0404 / 0.015 = 2.7h = 2h 42m.

22 Glasses of Wine, 140 lb Female, 1 Hour

Inputs

Drinks2 wines
Weight140 lbs
GenderFemale
Hours Elapsed1

Result

Estimated BAC5.175%
StatusImpaired
Time Until Sober3h 27m

Alcohol = 2 x 0.6 oz = 1.2 oz. BAC = (1.2 x 5.14) / (140 x 0.66) - (0.015 x 1) = 6.168 / 92.4 - 0.015 = 0.0668 - 0.015 = 0.0518. Displayed as (0.0518 x 100).toFixed(3) = 5.175%. Time = 0.0518 / 0.015 = 3.45h = 3h 27m.

Frequently Asked Questions

Q

How is BAC (Blood Alcohol Content) calculated?

BAC = (Alcohol in grams ÷ Body weight in grams × Gender constant) - (0.015 × hours elapsed). Widmark formula accounts for weight, gender, drinks, and time. Example: 180 lb man, 3 beers over 2 hours ≈ 0.04% BAC.

  • Widmark formula: BAC = (A × 5.14) ÷ (W × r) - (0.015 × H)
  • A = alcohol consumed in ounces, W = weight in lbs
  • r = gender constant (0.73 men, 0.66 women)
  • H = hours since drinking started
  • 0.015 = BAC metabolized per hour
Person2 Drinks4 Drinks6 Drinks
120 lb woman0.07%0.14%0.22%
160 lb woman0.05%0.11%0.16%
160 lb man0.04%0.09%0.13%
200 lb man0.03%0.07%0.10%
Q

What is the legal BAC limit for driving?

USA: 0.08% for 21+, 0.04% for commercial drivers, 0.00-0.02% for under 21 (zero tolerance). Utah: 0.05%. Many countries have lower limits. Impairment begins well before legal limit - even 0.02% affects driving.

  • Legal limit ≠ safe limit (impairment starts at 0.02%)
  • DUI can occur below 0.08% if impaired
  • First offense: $1,000-10,000+ fines, possible jail
  • Insurance rates increase 50-100% after DUI
LocationBAC LimitPenaltiesNotes
USA (most states)0.08%Fines, license suspension, jailPer se limit
USA (Utah)0.05%Same as aboveStrictest US state
USA (under 21)0.00-0.02%Immediate license suspensionZero tolerance
Commercial drivers0.04%CDL suspensionFederal law
UK0.08%VariesScotland: 0.05%
Australia0.05%Fines, suspensionAll states
Most EU countries0.05%VariesSome 0.00%
Q

How long until I am sober?

Body metabolizes ~0.015% BAC per hour (roughly 1 standard drink). From 0.08% → 0.00% takes ~5.5 hours. From 0.15% → 0.00% takes ~10 hours. Nothing speeds this up - not coffee, food, or cold showers. Only time works.

  • Metabolism rate: ~0.015%/hour (varies ±0.002%)
  • Coffee: Makes you a wide-awake drunk, doesn't help
  • Food: Only helps before/during drinking, not after
  • Exercise: Doesn't speed metabolism significantly
  • Sleep: Time passes, but you're still metabolizing at same rate
Starting BACTime to 0.08%Time to 0.05%Time to 0.00%
0.05%Already belowAlready below~3.5 hours
0.08%Already at~2 hours~5.5 hours
0.10%~1.5 hours~3.5 hours~7 hours
0.15%~4.5 hours~6.5 hours~10 hours
0.20%~8 hours~10 hours~13 hours
Q

What is a standard drink?

Standard drink = 0.6 oz (14g) pure alcohol. That's: 12 oz regular beer (5%), 5 oz wine (12%), 1.5 oz spirits (40%). Craft beers (8-12%) and cocktails often contain 1.5-3 standard drinks. Always check ABV.

  • Craft beers: Often 1.5-2 standard drinks per can
  • Restaurant wine pours: Often 6-8 oz, not 5 oz
  • Cocktails: Can contain 2-4 standard drinks each
  • Calculate total alcohol, not just number of drinks
Drink TypeServing SizeABVStandard Drinks
Light beer12 oz4%0.8
Regular beer12 oz5%1.0
Craft IPA12 oz7-9%1.4-1.8
Wine5 oz12%1.0
Wine (restaurant pour)6-8 oz14%1.4-1.9
Shot (vodka, whiskey)1.5 oz40%1.0
Margarita4-6 ozVaries1.5-2.5
Long Island Iced Tea8 ozVaries3-4
Q

Why do women have higher BAC than men?

Same drinks = higher BAC for women due to: 1) Lower body water (52% vs 61%) = more concentrated alcohol, 2) Less stomach enzyme (ADH) = more alcohol absorbed, 3) Generally lower body weight, 4) Hormonal fluctuations affect metabolism.

  • Body water: Women 52%, Men 61% - less dilution
  • Stomach enzyme ADH: Women have less, absorb more alcohol
  • Body weight: Lower weight = higher BAC
  • Hormones: BAC may be higher during certain menstrual phases
  • Same person: 3 drinks affects 120 lb woman more than 180 lb man
3 Standard Drinks120 lb Woman160 lb ManDifference
Estimated BAC0.10%0.05%2× higher
Time to 0.08%Already aboveBelow limitN/A
Time to sober~7 hours~3.5 hours2× longer
Q

What are the effects at different BAC levels?

Effects progress from relaxation (0.02-0.03%) to impaired judgment (0.05%) to legal intoxication (0.08%) to severe impairment (0.15%) to alcohol poisoning risk (0.25%+). Driving is impaired well before legal limit.

  • 0.02%: Impairment begins (1 drink for many people)
  • 0.05%: Clearly impaired, Utah legal limit
  • 0.08%: Per se DUI in most US states
  • 0.15%: High BAC, severe impairment
  • 0.30%+: Life-threatening, seek emergency care
BAC LevelEffectsDriving Impact
0.02-0.03%Relaxation, slight warmthSlight decline in visual function
0.05-0.06%Lowered inhibitions, impaired judgmentReduced coordination, harder to track objects
0.08%Poor muscle coordination, impaired reasoningConcentration difficult, speed control impaired
0.10-0.12%Slurred speech, poor balanceSignificantly impaired, reaction time very slow
0.15%+Major loss of balance, vomiting possibleSubstantial impairment - very dangerous
0.25%+Confusion, vomiting, may pass outRisk of alcohol poisoning

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Last Updated: Mar 9, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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