The science
Most apps assume alcohol hits you instantly. Reality is way more interesting. Let's walk through what your body actually does with that drink. You might start looking at that pre-game pizza differently.
When you drink, alcohol doesn't hit you all at once. It follows a curve — rising as your body absorbs it, peaking, then slowly falling as your liver breaks it down. The shape of that curve is what determines how you feel at any moment.
The problem? You can only feel where you were on the curve, not where you are. By the time you feel the last drink, you're already further along than you think. Keel shows you the curve in real time — so you can make decisions based on where you're heading, not where you've been.
Step by step
Alcohol doesn't just teleport into your blood when you drink. It takes a little trip through your body first, and the speed depends on a few things.1,6 Click through the stages to follow along.
Basically nothing happens here. Your mouth absorbs a teeny tiny amount of alcohol, but it's negligible. The real trip hasn't started yet.
The big insight
Most drink trackers add the full effect the second you log a drink. That creates a weird staircase pattern that doesn't match how you actually feel. In reality, alcohol absorbs gradually. The curve rises smoothly, peaking somewhere between 15 and 90 minutes after your drink.1,2
Toggle between the two models below. Same 3 beers, very different stories.
Same 3 beers, 30 minutes apart. The old model spikes instantly with each drink. The Keel model shows how alcohol actually absorbs over time.
The #1 variable
Your stomach is basically a bouncer. When it's empty, alcohol walks right through to your small intestine. But if you've eaten? The bouncer gets way stricter. Food keeps alcohol in the "waiting room" longer, which means it enters your blood more slowly.3
The formula
absorbed = 1 - e-ka × t
Where ka = 4 (3+ hours since eating) and t = hours since your drink
Personal math
Alcohol dissolves into your body's water. More water means more dilution. Think of it like food colouring in a glass vs a bucket. Keel estimates your body water from your weight, height, and biological sex.4,5 Play with the sliders.
Biological sex
45.1L body water
1 beer diluted across 45L of body water
Basic vs detailed
The basic model (Widmark, 1930s) only uses your weight and biological sex. The detailed model (Watson) goes further: it factors in your height and age to estimate your actual body water volume. Same drink, potentially different curve.4,5,8
Biological sex
Peak difference
23 ten-thousandths apart
Why Keel defaults to Detailed
Two people with the same weight can have very different amounts of body water. A tall 25-year-old and a shorter 60-year-old at the same weight will process the same drink differently. The detailed model captures that. The basic model treats them the same. Try moving the height and age sliders above and watch only the green curve move.
The speed limit
Your liver breaks down alcohol at a pretty fixed rate — about one standard drink per hour.1,6Coffee won't speed it up. Water won't either (but drink water anyway). It's like a single checkout lane at a supermarket. Same scanning speed no matter how long the line gets. More drinks just means a longer wait.
Your liver processes alcohol at about roughly one standard drink per hour, no matter what. One drink or six, same speed. The dashed amber line shows this constant rate. Add more drinks and watch the queue get longer.
Try the simulator on our homepage, or grab Keel to track your actual nights out.