Alcohol Impact Simulator — What It Is & How It Helps
This tool lets you estimate the impact of alcohol in a single session. It converts drinks into UK units, estimates BAC (blood alcohol concentration), shows a rough time to sober up, and highlights likely short-term effects (e.g., reaction time and coordination). It also adds alcohol-only calories and a note on how alcohol can stimulate appetite, helping people make more informed choices.
What the simulator calculates
- UK units — using:
(volume ml × ABV% ÷ 100) ÷ 10. (1 UK unit = 10 ml pure alcohol.) - BAC estimate — Widmark-style formula using body weight, sex (body water ratio), hours since first drink, and an adjustable metabolism rate.
- Recovery time — approximate hours to near-zero BAC (typical metabolism ~0.015% BAC/hour, adjustable 0.010–0.020).
- “Morning after” — estimated BAC remaining after a chosen sleep duration (e.g., 8 hours).
- Alcohol-only calories — ethanol grams × 7 kcal (ethanol ≈ 0.789 g/ml). Mixers/food can add more.
How this helps people
- 🔎 Clarity — turns pints, wines, and shots into comparable units and a single BAC estimate.
- 🧭 Safer planning — shows rough time to sober up and a morning-after estimate to avoid risky decisions.
- 📏 Guideline awareness — compares a session to the UK’s 14 units/week low-risk guideline, encouraging drink-free days.
- 🍟 Appetite insight — explains alcohol’s tendency to increase appetite and reduce self-control, which can lead to extra eating.
- 🔥 Calorie visibility — shows alcohol-only calories to support weight- and health-related goals.
How to use it
- Enter your body weight, select sex, and set hours since first drink.
- Add drinks from the searchable list (beer, wine, spirits, alcopops, cocktails) or add a custom drink with ml and ABV.
- Review your Units, BAC, recovery time, morning-after, and calories.
- Use the results for awareness and planning—not for deciding whether to drive.
What alcohol does at common BAC levels
- 0.02–0.04%: mild relaxation; reduced judgment/divided attention.
- 0.05–0.08%: slowed reactions; impaired coordination and tracking.
- 0.08%+: high crash risk; illegal to drive in England/Wales (Scotland ≈ 0.05%).
- 0.15%+: severe impairment; blackouts possible. 0.30%+: medical emergency risk.
Alcohol & appetite: why you may eat more
Alcohol can increase appetite via brain reward pathways and reduces self-control, so people often choose
saltier, fattier foods and larger portions. It can also disturb sleep, which may raise hunger hormones the next day.
Limits & important notes
- Estimates only: Individual absorption/metabolism vary widely (age, health, meds, food, genetics).
- Not a legal or medical tool: Do not use to decide if you’re safe/legal to drive. Police tests are definitive.
- Guidelines: Men & women—aim not to regularly exceed 14 units/week, spread over 3+ days with several drink-free days.
- Calories shown are from alcohol only; mixers/ingredients can significantly increase totals.
Method overview: Units use the UK formula (1 unit = 10 ml ethanol). BAC is a Widmark-style estimate using weight, sex-based body water ratio, drinking duration, and a selectable metabolism rate (~0.010–0.020% per hour; default 0.015%).
