Breastfeeding Alcohol Calculator: How Long After Drinking Can I Breastfeed?

This breastfeeding alcohol calculator estimates when the alcohol from your drinks should be out of your breast milk, so you can plan your next feed. Enter your weight and height, what you drank and when you started. The calculator compares two numbers and shows the later one: a body-weight estimate of how long your body needs to clear the alcohol, and the CDC’s minimum of 2 hours per drink.

Not drinking is the safest choice while breastfeeding. But moderate drinking, up to one drink a day, is not known to be harmful to a breastfed baby, especially if you wait before nursing. For the full picture, read our guide to breastfeeding and alcohol.

How long alcohol stays in breast milk

Times from the start of drinking, calculated by us for a woman 5 ft 4 in tall, rounded up to the next minute. The calculator adjusts for your own height and weight.

Your weight	1 drink	2 drinks	3 drinks	4 drinks
110 lb (50 kg)	2 h 43 min	5 h 25 min	8 h 08 min	10 h 50 min
130 lb (59 kg)	2 h 31 min	5 h 01 min	7 h 31 min	10 h 01 min
150 lb (68 kg)	2 h 20 min	4 h 40 min	7 h 00 min	9 h 19 min
170 lb (77 kg)	2 h 11 min	4 h 22 min	6 h 32 min	8 h 43 min
190 lb (86 kg)	2 h 03 min	4 h 06 min	6 h 08 min	8 h 11 min
210 lb (95 kg)	2 h 00 min*	4 h 00 min*	6 h 00 min*	8 h 00 min*

* The body-weight estimate is a little shorter here, so the CDC minimum of 2 hours per drink applies.

For comparison, the CDC says alcohol can generally be detected in breast milk for about 2 to 3 hours after 1 drink, 4 to 5 hours after 2 drinks and 6 to 8 hours after 3 drinks, and LactMed advises waiting 2 to 2.5 hours per drink. Our times for lighter women can run a little longer than the CDC’s windows because we count from the start of drinking and round up.

How the calculator works

Alcohol passes freely between your blood and your milk, so the level in your milk rises and falls with your blood alcohol level. It peaks about 30 to 60 minutes after a drink, a little later if you eat.

1. Standard drinks. We count each 12 oz beer (5%), 5 oz glass of wine (12%) and 1.5 oz shot of spirits (40%) as one US standard drink of 14 grams of alcohol.
2. Peak blood alcohol. Alcohol spreads through the water in your body. We estimate your total body water from your height and weight (the Watson formula for women) and work out the peak blood alcohol level.
3. Time to clear. The body clears alcohol at a fairly steady rate; we assume about 0.015 g/dL per hour, a commonly used average that varies from person to person. Dividing the peak by that rate gives the hours until the alcohol is gone, counted from your first drink. This is the same kind of calculation as the Motherisk time-to-zero table (Ho 2001; Koren, 2002), but we have not matched that table’s exact parameters, so our times may differ from its published values.
4. CDC minimum. We also apply the CDC’s advice of waiting 2 hours per drink, and show you whichever time is later.

Two choices are ours, to stay on the cautious side: the calculator assumes all your drinks were close together, counting from the first one, and it rounds the time up to the next minute. If you spread your drinks over the evening, the alcohol may be gone a little sooner.

Planning ahead

• Feed or pump right before you drink. That gives you the longest stretch before the next feed.
• Have expressed milk ready. Milk pumped before drinking is fine to give while you wait. See our breast milk storage guide.
• Pump for comfort only. If your breasts get full while you wait, pump and throw that milk away. It doesn’t speed anything up.
• Eat while you drink. Food slows how fast alcohol reaches your blood.

Important safety notes

• Heavy drinking (for women, 4 or more drinks on any day, as the NIAAA defines it) is not recommended while breastfeeding. The CDC advises no more than one drink a day. Plan for a sober adult to care for your baby.
• Safe sleep: never bed-share or fall asleep with your baby on a sofa or armchair after drinking.
• Don’t drive after drinking, whatever the calculator says about your milk.
• This calculator is an estimate for healthy adults. Alcohol is cleared more slowly by some people, for example with liver conditions or some medicines. Newborns and premature babies are more sensitive, so be extra cautious in the early weeks. It does not replace advice from your doctor.

For other questions about what’s safe while breastfeeding, see our medicines and safety guide.