The Nightcap Curve
Is your nightcap still with you at 2 a.m.? Log tonight's drinks and your bedtime to see how far into your sleep the alcohol is still clearing — through the stretch of the night it disrupts most — and the honest range your body might really be in.
14 g alcohol
5 oz wine · 12 oz beer · 1.5 oz spirits (US; CA uses 13.45 g)
~1 drink / 1.5–2 h
≈0.015%/h — and it genuinely varies person to person
Back half of the night
REM suppression while alcohol is still clearing
Each drink becomes a standard-drink amount of pure alcohol, absorbs over about 45 minutes, and then clears at a steady rate — roughly one standard drink every hour and a half to two hours. Unlike caffeine, alcohol leaves at a fixed pace, so two drinks take about twice as long as one. Because clearance truly varies — body size, sex, food, genetics — we always draw a range, not a single confident line.
Alcohol can make falling asleep feel easier — then collect the debt later. Sleep research links the hours when alcohol is still clearing, concentrated in the second half of the night, with suppressed REM and more fragmented sleep. That's the stretch this tool shades: see how far tonight's drinks reach into it, and how much an earlier last call pulls them back.
Method & Sources
We convert each drink to a standard drink (US: 14 g of pure alcohol; Canada: 13.45 g) and model clearing with a Widmark-based estimate — alcohol absorbing over ~45 minutes, then leaving at about 0.015% per hour. Everyone metabolizes alcohol differently — by body size, sex, food, genetics, and more — so the shaded band shows a slower-to-faster range (roughly 0.010–0.020%/h), wider if you skip the optional body inputs. The vertical axis is an educational estimate, not a measured reading. The shaded window marks the stretch of your sleep while alcohol is still clearing — published sleep research associates that clearing period, concentrated in the back half of the night, with REM suppression and fragmented sleep.
Educational, Not Medical Advice
Daily Vitality tools organize information and published guidance — they don't diagnose conditions, and they're not a substitute for care. Talk with your doctor, pharmacist, or another clinician about what's right for you.
Never use this tool to judge whether it's safe to drive. And if alcohol or sleep is a recurring struggle, that's a conversation worth having with a clinician — this tool can't assess alcohol use or diagnose a sleep problem.
Sources: standard-drink definitions — US Dietary Guidelines (14 g) and CCSA, Canada's Guidance on Alcohol and Health, 2023 (13.45 g), retrieved July 2026. Pharmacokinetics: Widmark distribution (r ≈ 0.68 men / 0.55 women) with zero-order elimination ~0.015%/h (range ~0.010–0.020%/h), per published alcohol-metabolism literature. Sleep effects: REM suppression and sleep fragmentation concentrated in the second half of the night as alcohol clears (e.g., Ebrahim et al., 2013 — citation string pending clinician review). Weekly guidance quoted verbatim from the US Dietary Guidelines and CCSA 2023. This tool stores nothing you enter — your inputs live only in this page's URL.