Accutane / Isotretinoin Cumulative Dose Calculator
Free educational Accutane / isotretinoin cumulative dose calculator: mg/kg from total mg and weight, optional hypothetical target math, scenario sensitivity rows—plus a long guide. Not medical advice or prescribing.

Prescription safety notice: Isotretinoin is a high-risk prescription medicine with strict programs (for example REMS in the United States) and serious pregnancy risks. This page is educational only. It does not tell you what to take, change your dose, or replace your dermatologist, pharmacist, or program requirements. Never start, stop, split, or “recalculate” medication without licensed medical guidance.
Summary: Many clinicians discuss isotretinoin using total milligrams per kilogram of body weight over a course (cumulative mg/kg). This tool helps you do the arithmetic—like a mortgage calculator’s “what-if” rows—so you can understand numbers you already received from a prescriber or pharmacy record. It does not pick a daily tablet strength for you.
What this tool does — and does not (tap to expand)
- Does: converts your entered total mg and weight (kg) into cumulative mg/kg, shows a few sensitivity rows (±5% on totals or weight—illustrative only), and optionally estimates total mg for a hypothetical cumulative target mg/kg you type in for classroom-style discussion with a clinician.
- Does not: interpret labs, manage side effects, handle pregnancy prevention testing, or replace program enrollment, dispensing rules, or individualized prescribing decisions.
“Accutane®” is a registered trademark used here in a descriptive sense; this site is not affiliated with the brand owner. Generic isotretinoin is prescribed under many names and strengths.
Isotretinoin (Accutane) cumulative dose calculator
Enter numbers from your care team or pharmacy totals. After you calculate, you will see your baseline cumulative mg/kg, a small scenario table (similar spirit to the mortgage calculator’s stress rows), and—if you fill it in—an illustrative total mg line for a hypothetical cumulative target mg/kg (not a recommendation).
Assumptions & methodology (short)
- Cumulative mg/kg = total isotretinoin milligrams ÷ body weight in kilograms.
- Total mg illustrative line = (target mg/kg) × (weight kg). Targets vary by person, region, tolerability, and clinician judgment.
- Scenario rows adjust only one input at a time (±5% total mg, or ±5% weight) to show how sensitive the ratio is to rounding or record-keeping error—not to suggest changing your real dose.