How accurate is the Widmark formula?

Widmark gives a useful estimate but is not legally definitive. Individual variation in metabolism, food intake, hydration, body composition and medication can shift true BAC by ±20–30%.

How long does alcohol take to leave the system?

The body metabolises about 0.015% BAC per hour. A peak BAC of 0.08% takes approximately 5.3 hours to fully clear. Coffee, cold showers and food do not speed this up.

Is this a substitute for a breath or blood test?

No. Use as an educational guide only. If your BAC matters legally or medically, use a certified breathalyser or blood test.

🍺 Blodalkohol Content (BAC) Lommeregner

Estimér dit blodalkoholindhold ved hjælp af Widmark-formlen — den internationalt anerkendte videnskabelige standard. For educational purposes only. Kør aldrig bil eller betjen maskiner efter at have drukket. Alle beregninger kører i din browser — ingen data gemmes.

Biologisk Køn

Unit System

Kropsvægt (kg)

Timer siden første drink

FORBRUGTE DRINKS

🍺 Øl / Cider (pint, 4,5%)

🍷 Vin (175 ml glas, 13%)

🥃 Spiritus (25 ml skud, 40%)

🍹 Cocktails (avg. 1.5 units each)

⚠️ IMPORTANT: Denne beregner er til educational purposes only. BAC-estimater er meget variable og afhænger af faktorer, dette værktøj ikke kan tage højde for (madindtag, medicin, helbredstilstande, hydrering). Never drive after drinking, regardless of what this calculator shows. Den eneste sikre BAC til kørsel er 0,00%.

Om denne lommeregner

The BAC Calculator uses the Widmark formula — the scientific standard for estimating blood alcohol concentration — developed by Swedish physician Erik Widmark in the 1920s and still used by forensic and medical experts today.

Widmark-formlen

BAC (%) = (Alkohol forbrugt i gram ÷ (Kropsvægt i gram × Kønskonstant r)) − (Metabolismerate × Timer)

r (distribution ratio): 0,68 for mænd, 0,55 for kvinder (afspejler forskellige kropsvandsprocentdele)
Metabolism rate: 0,015% BAC pr. time (gennemsnitlig voksen levers elimineringshastighed)

BAC referenceguide

0.00–0.02%: No notable impairment for most people
0.02–0.05%: Let afslapning, let nedsættelse af bedømmelse
0.05–0.08%: Reduceret koordination, langsommere reaktionstider — illegal to drive in most of Europe
0.08–0.15%: Betydelig nedsættelse — sløret tale, balanceproblemer
0.15–0.30%: Severe impairment, high risk of blackout
Above 0.30%: Risiko for alkoholforgiftning — medicinsk nødsituation

Legal Driving Limits

Ireland, Germany, France, Spain, Netherlands: 0,05%
Czech Republic, Hungary, Slovakia, Romania: 0.00%

⚠️

Vigtig bemærkning: This tool is intended to provide estimates and should not be used as a substitute for professional advice. BAC varies significantly based on food intake, medications, individual metabolism, and health status. Never rely on this calculator to make decisions about driving or operating machinery. If in doubt, don't drive.

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