Bioequivalence Calculator
Why 80–125%? Regulatory range for safe clinical interchange.
Example: If Cmax (test) = 90, reference = 100 → Ratio = 90% → Acceptable
Bioequivalence Calculator – Understand AUC, Cmax, and More
The Bioequivalence Calculator is an essential tool for pharmacy students and professionals. It helps you compare two drug formulations – a test drug and a reference drug – to see if they behave the same in the body. This comparison is called bioequivalence testing.
The tool uses key pharmacokinetic parameters like Cmax, AUC, and Tmax to make this decision. It also gives you an easy-to-read result and a clear color-coded interpretation. This tool is perfect for students learning pharmacokinetics, and for researchers handling bioequivalence data.
What Is Bioequivalence?
Bioequivalence means two drugs work the same way in the body. If a generic drug and a brand-name drug have similar Cmax (maximum concentration) and AUC (total drug exposure), they are considered bioequivalent.
Regulatory agencies like the US FDA accept a range of 80% to 125% for AUC and Cmax ratios between test and reference drugs. If both values fall within this range, the drugs are bioequivalent.
This tool does the calculations for you, shows a visual chart, and clearly tells whether your drugs pass or fail.
Why Use This Calculator?
Calculating bioequivalence by hand can be tricky. It involves multiple steps, formulas, and conversions. This calculator makes it easy.
Just input the basic data from your pharmacokinetic study:
Cmax of the test drug
Cmax of the reference drug
AUC of the test drug
AUC of the reference drug
Tmax values (optional)
Click “Calculate,” and the tool does the rest. It checks the values, calculates the ratios, and shows the results.
Key Features of the Bioequivalence Calculator
This tool includes several smart and student-friendly features:
Responsive Layout
On desktop, the input and output sections appear side by side. On mobile, they stack vertically for easy scrolling. It works smoothly on all screen sizes.
Instant Calculation
Enter the required data, and the calculator instantly computes:
Cmax Ratio (%)
AUC Ratio (%)
Tmax Difference (optional)
Bar Chart Visualization
The results are shown in a colorful bar chart. This makes it easy to compare how close the test drug values are to the reference drug.
The acceptable range (80% to 125%) is shaded in green. The calculated Cmax and AUC ratios are plotted on this scale. This gives you a quick visual verdict.
Verdict with Color Code
The tool instantly shows whether your test drug is bioequivalent to the reference drug.
Green: Passes both AUC and Cmax criteria
Yellow: One passes, one fails – borderline
Red: Fails both criteria
This color-coded output helps you understand the result without doing extra interpretation.
Educational Tooltips
Every input field has a small info icon. Hover or tap to read definitions and tips:
What is Cmax?
What does AUC mean?
Why is Tmax optional?
These tooltips help students understand what they are entering and why it matters.
Input Validation
The tool only accepts numeric inputs. Cmax and AUC must be positive numbers. It prevents typing errors and warns if something is missing.
Export Options
You can export your result as a PNG image (graph only) or a PDF file (includes chart + results).
Use these files for lab reports, class presentations, or personal study notes. No need to copy data manually.
Reset Button
Use the Reset button to clear all values and start a fresh calculation.
How to Use the Bioequivalence Calculator
Follow these easy steps:
Step 1: Enter the Pharmacokinetic Values
Fill in the four required fields:
Cmax (Test)
Cmax (Reference)
AUC (Test)
AUC (Reference)
Optionally, enter:
Tmax (Test)
Tmax (Reference)
Tmax is not required for bioequivalence verdict, but helps understand absorption rate.
Step 2: Click “Calculate”
The calculator instantly shows:
Cmax Ratio in %
AUC Ratio in %
Tmax difference (if given)
Graph with plotted results
Color-coded verdict (Pass/Fail)
Step 3: Analyze the Graph
The green zone on the bar chart marks the acceptable 80%–125% range. See where your drug stands. If both bars fall within the green zone, your test drug is bioequivalent.
Step 4: Export or Reset
Click Export to download results in PNG or PDF format. Click Reset to clear all data and start again.
Understanding the Output: Key Parameters
Cmax
This is the maximum plasma concentration a drug reaches after administration. It shows how fast and how much drug is absorbed.
The calculator finds:
Cmax Ratio = (Cmax Test / Cmax Reference) × 100
Example:
If Cmax Test = 88 and Cmax Ref = 100 → Cmax Ratio = 88%
AUC
AUC stands for Area Under the Curve. It represents total drug exposure over time.
The calculator finds:
AUC Ratio = (AUC Test / AUC Reference) × 100
Example:
If AUC Test = 1250 and AUC Ref = 1000 → AUC Ratio = 125%
Tmax
Tmax is the time at which Cmax occurs. It’s optional in this calculator. The tool calculates the time difference between Test and Reference Tmax if given.
Educational Value for Pharmacy Students
This calculator is more than just a tool – it’s a learning resource.
Understand how ratios are calculated
See how close values should be for FDA approval
Learn the importance of bioequivalence in generic drug approval
Get instant interpretation, saving time in labs and assignments
Visualize pharmacokinetic differences
It also builds a foundation for advanced topics like therapeutic equivalence, drug regulation, and biowaivers.
Use Cases and Applications
Students: Solve bioequivalence case studies and assignments
Researchers: Quickly check ratios before deeper analysis
Educators: Use live in class to teach AUC/Cmax comparison
Pharmacists: Understand generics and FDA submission basics
