How much does alcohol lower HRV?

Dose-dependent. In a controlled study, one drink moved overnight HRV essentially not at all; two drinks dropped total HRV by about 28–33%. Real-world wearable data shows overnight RMSSD falling roughly 2 ms at a low dose, 6 ms at a moderate dose, and 13 ms at a high dose. The honest takeaway is a direction and a range relative to your own baseline, not a precise number.

How long does HRV take to recover after drinking?

A single drink should clear by the next night. A couple of drinks typically keep HRV below your baseline for 1–2 nights; heavier nights, 1–3+ nights. Bigger nights take longer, and repeated heavy drinking can keep HRV depressed for longer still.

Is there a safe amount of alcohol for HRV?

This tool doesn't frame any amount as safe — it only estimates the recovery cost. The effect is dose-dependent and individual, so it gives you a within-person ballpark rather than a threshold to aim at.

Tool

How much did last night’s drinks cost your HRV?

Alcohol is the single cleanest cause-and-effect you’ll find in your own HRV data. Enter what you drank and your typical range, and this tool estimates how far tonight’s reading is likely to fall below your baseline — and when it should be back. It gives a direction and a hedged range, never a fake-precise number, and never a “safe amount” to aim at.

Last night’s drinks

Standard drinks you had (or are planning tonight). One standard drink ≈ a 355 ml beer, 150 ml wine, or 45 ml spirits.

Standard drinks

Your typical overnight range

From your app’s 7-day average — roughly your normal low and normal high. Not a target; just where you usually sit when you haven’t been drinking.

Normal low

Normal high

Your device (optional)

Enter how many drinks you had and your typical overnight range to see roughly how much tonight’s HRV might drop, and when it should clear.

A low reading the morning after a few drinks isn’t a separate alarm — it’s the drink, already explained. For why alcohol dominates the suppressor list, what else moves your number, and how to read your baseline, see the HRV guide.