Pharmaceutical Tools
Tablet Count Calculator
Calculate the total number of tablets or capsules required for a complete course of treatment — including optional dispensing buffer and days-supply check.
Formula
Total tablets = ⌈(Dose ÷ Tablet strength) × Frequency × Duration⌉
Dose = dose per administration (mg, mcg, or g)
Tablet strength = strength per tablet (same unit)
Frequency = doses per day
Duration = days
Tablets per dose
—
Total tablets
—
tablets
How to Use This Calculator
1
Enter the prescribed dose per administration and select the unit (mg, mcg, or g).
2
Enter the tablet or capsule strength in the same unit as the dose.
3
Select the dosing frequency and enter the treatment duration in days.
4
Optionally enter a buffer percentage for PRN medications and the quantity on hand for a days-supply check.
5
Click Calculate. The result shows tablets per dose, total tablets, buffer quantity, and days supply.
Examples
Amoxicillin 500 mg, 3× daily, 10 days, 500 mg tablets: 1 tablet × 3 × 10 = 30 tablets
Metoprolol 50 mg, twice daily, 30 days, 25 mg tablets: 2 tablets × 2 × 30 = 120 tablets
Frequently Asked Questions
Multiply tablets per dose × doses per day × 30 days. For example, 1 tablet twice daily = 1 × 2 × 30 = 60 tablets. If the dose requires more than one tablet per administration, multiply accordingly (e.g. 2 tablets twice daily × 30 days = 120 tablets).
Check whether the tablet is scored — scored tablets can usually be halved safely. If the tablet is unscored, extended-release, enteric-coated, or a capsule, contact the prescriber to adjust the dose or switch to an available strength that avoids splitting (e.g. use two 25 mg tablets instead of one 50 mg, or prescribe a 12.5 mg strength).
Days supply = tablets on hand ÷ (tablets per dose × doses per day). Enter the tablets on hand in the optional field and this calculator will compute the days supply automatically.
A dispensing buffer is an extra percentage of tablets (typically 5–10%) added to the calculated quantity. This is used for PRN (as-needed) medications, to account for accidental loss or spillage, or to ensure patients do not run out before the next prescription. A 10% buffer on 30 tablets yields 33 tablets dispensed.
For tablet count purposes, both are equivalent — 2 doses per day. Clinically, "twice daily" (BID) gives the patient flexibility to take doses morning and evening, while "every 12 hours" implies strict timing for drugs needing consistent plasma levels, such as certain antibiotics or antiretrovirals.