Breast Milk Storage Calculator (Use-By Date & Time)

How it works

use-by = time pumped (or thawed) + safe storage time · countertop 4 h · insulated cooler 24 h · refrigerator 4 days · freezer best ≤ 6 months, acceptable ≤ 12 months · thawed: 1–2 h at room temperature or 24 h in the fridge · leftover milk: 2 h after the feeding (CDC)

Freshly pumped breast milk keeps for up to 4 hours at room temperature (up to 77 °F / 25 °C), 4 days in the refrigerator and about 6 months in the freezer for best quality, 12 months at most. Once frozen milk is thawed the clock is much shorter — use it within 1–2 hours at room temperature or within 24 hours in the fridge, and never refreeze it. Milk the baby has started drinking should be finished or thrown away within 2 hours. These are the CDC guidelines for healthy full-term babies; hospitals use stricter rules for premature or sick infants.

Worked example

Milk pumped at 09:00 and put straight into the refrigerator should be used within 4 days — by 09:00 on the fourth day after pumping. If you freeze it instead, it is best used within 6 months and acceptable for up to 12 months. If you thaw a bag in the fridge, use it within 24 hours of being fully thawed.

Sources: CDC: Breast milk storage and preparation · Academy of Breastfeeding Medicine Protocol #8: Human milk storage (2017)

Frequently asked questions