Hangover Duration Calculator
Estimate how long your hangover will last based on drinks consumed, body weight, sleep, and hydration.
Hangover duration depends on how much you drank, your body weight, hydration level, sleep quality, and individual tolerance. Most hangovers last 12–24 hours, but heavy drinking can cause symptoms lasting 72 hours.
How alcohol causes hangovers: Your liver processes alcohol at approximately one standard drink per hour. When you drink faster than this rate, acetaldehyde (a toxic byproduct) builds up, causing nausea, headache, and fatigue. Alcohol also suppresses vasopressin (antidiuretic hormone), causing dehydration and electrolyte imbalance.
Standard drink sizes:
- Beer (5% ABV): 12 oz / 355 ml
- Wine (12% ABV): 5 oz / 148 ml
- Spirits (40% ABV): 1.5 oz / 44 ml
Body weight matters: A 200 lb (91 kg) person processes alcohol faster than a 130 lb (59 kg) person because they have more blood volume and liver tissue. Body composition also plays a role — muscle tissue contains more water than fat, so more muscular people dilute alcohol better.
Dehydration is the biggest factor: Each alcoholic drink causes your body to expel 120–160 ml more fluid than it takes in. A night of 6 drinks can create a fluid deficit of nearly a liter, causing the classic headache and dry mouth.
Sleep quality: Alcohol disrupts REM sleep, even if you sleep a full 8 hours. The restorative phases of sleep are shortened, which is why you feel exhausted even after a long sleep.
Recovery tips: Drink water between alcoholic drinks (1:1 ratio). Eat before and during drinking — food slows alcohol absorption. Electrolyte drinks help more than plain water the morning after. Avoid acetaminophen (Tylenol) — it stresses the liver. Ibuprofen is safer for headaches. Time is the only true cure.
Congeners: Dark spirits (whiskey, red wine, brandy) contain more congeners (fermentation byproducts) than clear spirits (vodka, gin, white wine), which can worsen hangover symptoms.