Medication Days Supply
Enter the quantity dispensed and Sig instructions to calculate days supply, next refill window, and projected therapy completion when refills are used consecutively.
Tablets/capsules dispensed or total mL for liquids.
Example: "Take 1 tablet" → units per dose = 1.
BID = 2, TID = 3, every other day = 0.5.
Enter integer number of permitted refills.
Schedule Overview
Days supply
90.0 days
1.00 unit(s) used per day.
Next refill
Jul 30, 2026
Early pickup allowed starting Jul 23, 2026.
Therapy end
Jan 26, 2027
3 fill(s) total (original + 2 refills).
How to Use This Calculator
Translate the Sig
Convert directions (e.g., “1 tablet twice daily”) into units per dose and doses per day.
Enter dispense quantity
Use total tablet count, capsule count, or mL for liquids/insulins.
Review refill timing
Plan follow-ups, prior authorizations, and patient reminders based on the projected refill window.
Formula
Daily use = units per dose × doses per day.
Adapted from pharmacy dispensing standards and insurance refill policies.
Frequently Asked Questions
How do I account for PRN use?
Use the maximum likely daily usage to ensure the patient does not run out early. Document assumptions.
What if the patient stockpiles doses?
Adjust the start date to the actual pickup date and recalculate remaining supply based on doses taken.
Can I use this for topical or inhaled meds?
Yes, if the Sig can be converted into units/day. For sprays/puffs, set “units per dose” to number of actuations.
Do insurance plans follow the same early refill window?
Many plans allow 75–80% usage before refill; controlled substances may have stricter rules. Confirm with payer.
How should leftover medication affect the next fill?
Subtract remaining tablets from the quantity needed before sending the next prescription to avoid duplication.