Accumulation Ratio Calculator

Published August 19, 2026

Calculate the accumulation ratio of a drug during repeated dosing.

Formula:
Accumulation Ratio (R) = 1 / (1 − e^−kτ)

where k = elimination rate constant and τ = dosing interval.

Drug Half-Life

Enter half-life in hours

Dosing Interval (τ)

Enter dosing interval in hours

Accumulation Ratio

Half-Life —

Dosing Interval —

Elimination Rate Constant (k) —

This calculator assumes first-order elimination and a constant dosing interval. It is intended for educational and pharmacokinetic calculations and should not replace clinical judgment.

``` ### Formula used **Elimination rate constant:** `k = ln(2) / t½` **Accumulation ratio:** `R = 1 / (1 − e^−kτ)` For example, with a **half-life of 8 hours** and a **12-hour dosing interval**, the calculator gives an accumulation ratio of approximately **1.333**. This version is **standalone**, responsive, animated, and suitable for placing inside a WordPress Custom HTML block.