PumpStash
Free calculator

Breast Milk Stash Calculator

How long will your freezer stash actually last? Enter what you have and what your baby drinks to see your days of cover and when you'll run out.

Stash calculator

See how many days of feeds your freezer stash holds.

Milk stash on hand
oz
Baby's daily intake
oz/day

Enter your stash and your baby's daily intake to see how long it lasts.

A planning estimate based on a steady daily intake. Babies' needs change day to day, so treat it as a guide, not medical advice.

How the math works

Days of cover is just your stash divided by daily intake: stash ÷ daily intake = days. A 150 oz stash and a baby drinking 30 oz a day gives you five days. The hard part isn't the division — it's knowing your real numbers, because a stash is dozens of bags frozen on different dates, and intake drifts as your baby grows.

For the most accurate result, use your baby's recent average intake rather than a round guess, and count your stash by the bag if you freeze in a consistent size. When you're done here, the breast milk storage guide covers how long each bag stays good in the fridge and freezer so none of your runway goes to waste.

Let your stash count itself

This calculator is a snapshot. PumpStash keeps it live: log each bag with its size and freeze date, and the app tracks your stash total, projects your days of cover as it changes, and flags the milk to thaw next — no spreadsheet, no mental math at 3 a.m.

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Stash calculator FAQ

How do I calculate how long my breast milk stash will last?
Divide your total stash by your baby's daily milk intake. For example, a 120 oz stash with a baby drinking 25 oz a day lasts about 4.8 days (120 ÷ 25). The calculator above does this for you and estimates the run-out date.

How much milk does a baby drink per day?
Most exclusively milk-fed babies from about 1 to 6 months take roughly 24–30 oz (710–890 ml) per day, often 2–4 oz per feeding across 8–12 feeds. Intake varies by baby and slows once solids start, so use your baby's actual recent feeds for the most accurate estimate.

How big is a typical bag of frozen breast milk?
Most parents freeze milk in 2–4 oz (60–120 ml) portions, which thaw quickly and waste less. If you store in a consistent size, switch the calculator to 'Bags' mode and enter your bag count times the ounces per bag.

Does this calculator account for milk I'm still pumping?
Not yet — it estimates how long a fixed stash lasts at a steady intake, which answers the most common 'how long will it last' question. If you're still pumping, your stash will last longer than the estimate, since fresh milk offsets what your baby drinks.