Medication Days Supply Cheat Sheet
A basic math reference for estimating days supply from quantity and daily use. Designed for planning and education. Always follow your prescription label.
Basic Formulas
Tablets or capsules
Days supply = quantity dispensed ÷ tablets per day
Example: 30 tablets ÷ 1 per day = 30 days supply
Multiple tablets per dose
Tablets per day = tablets per dose × doses per day
Example: 2 tablets per dose × 2 doses per day = 4 tablets per day
Liquid medicine (mL)
Days supply = total mL ÷ mL per day
Example: 300 mL ÷ 10 mL per day = 30 days supply
mL per day for liquids
mL per day = mL per dose × doses per day
Example: 5 mL per dose × 2 doses per day = 10 mL per day
Eye drops from bottle volume
Total drops ≈ mL × 20 (common estimate)
Example: 5 mL × 20 drops/mL ≈ 100 drops
Quick Examples
| Quantity | Daily use | Estimated days supply |
|---|---|---|
| 30 | 1 per day | 30 days |
| 60 | 2 per day | 30 days |
| 45 | 1.5 per day | 30 days |
| 300 | 10 per day | 30 days |
| 5 | N/A (bottle volume) | ≈ 100 drops (5 mL × 20 drops/mL) |
Practice Problems
Try these on your own. Write your answers in the right column.
| Problem | Your answer |
|---|---|
| 60 tablets, 1 per day | ____________________ |
| 90 tablets, 3 per day | ____________________ |
| 120 tablets, 2 per day | ____________________ |
| 450 mL, 15 mL per day | ____________________ |
| 10 mL eye drops, 1 drop in both eyes twice daily | ____________________ |
Related Calculators
Safe use note: This cheat sheet is for basic math practice and planning only. Always follow the prescription label and ask a pharmacist or prescriber about medication-use questions. Actual days supply may vary based on dose adjustments, missed doses, or prescriber instructions.