How this calculator works
The model balances milk consumed and milk available over a chosen horizon. It assumes constant daily intake and output, a usable starting stash and no waste. The optional buffer is a user-selected planning allowance, not a feeding recommendation. Existing milk offsets the total volume needed; pumping during the plan contributes additional milk, including milk consumed on pumping days. Age inputs use average month durations rather than calendar dates. Storage expiry, supply changes and gradual weaning are not modelled. CDC milk-handling limits apply independently of the arithmetic. The result is an estimate for information only and is not medical advice.
Formula
Let D be daily use including buffer, P daily pumping, S starting stash and H the planning horizon in days. Pumping days = max(0, (D H - S)/P), provided this is no more than H. With T planned pumping days, total coverage = (S + P T)/D.
Worked example
For 750 mL/day use, 900 mL/day pumping, no starting stash and a 60-day horizon, pump for 50 days. The accumulated surplus then supplies the final 10 days. A 3000 mL stash with 600 mL/day pumping for 10 days supplies 12 days at 750 mL/day.
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Frequently asked questions
Why not divide the target stash by daily surplus?
Daily use after pumping stops decreases as the stopping date moves later. Balancing total supply against total use accounts for both periods.
Does the calculator prescribe a daily intake?
No. Enter your own measured or clinician-agreed daily volume. The default is only an example.
Can all frozen milk count toward the stash?
Only milk that remains suitable under safe storage and handling guidance should count. A numeric balance does not check expiry or a baby's individual needs.