Cobb test Calculator in Excel
Professional free tool to calculate water resistance in paper and cardboard according to TAPPI T 441 standard. Get automatic results with average, range interpretation and complete guide included.
Calculation Formula:
Cobb (g/m²) = (final mass − initial mass) × 10,000 / tested area (cm²)
- Automatic Calculator
- How to Take Cobb
- Results Interpretation
Why use our calculator?
Everything you need to perform and analyze the Cobb test in one professional tool.
Save time
Automatic calculations with average of up to 5 samples. Forget manual formulas.
Official standard
Based on TAPPI T 441 standard for accurate and reliable results.
Expert guide
Includes step-by-step instructions and results interpretation table.
100% Free
No hidden costs, no subscriptions. Just enter your data and download.
What is included in the calculator?
A complete tool that includes everything needed to perform the Cobb test professionally.
About Coaterex
Learn about our experience in water-based coatings and paper technology.
What is the Cobb test?
Understand the basis of this standardized test for measuring water absorption.
Step-by-Step procedure
Detailed guide with necessary equipment and times according to TAPPI T 441.
Automatic calculator
Enter initial and final weights of up to 5 samples and get automatic results.
Results interpretation
Complete reference table to evaluate the water resistance of your materials.
Results Interpretation
Ranges are illustrative, not standard limits or performance guarantees. Define acceptance according to test duration, material and end use.
| Cobb Range | Resistance level | Recommended Applications |
|---|---|---|
| < 10 g/m² | Very good resistance | Refrigerated, plastic replacement, high-demand packaging |
| 10–20 g/m² | Good resistance | Standard packaging and labels, dry products |
| 20–50 g/m² | Moderate resistance | Controlled humidity, dry environments, indoor use |
| > 50 g/m² | Low resistance | Requires more protection, limited use, untreated materials |
Frequently asked Questions
Answers to the most common questions about the calculator and the Cobb test.
Is the calculator really free?
Yes, the calculator is completely free. You just need to complete the form with your information to receive it in your email. There are no hidden costs or mandatory subscriptions.
What standard does the calculator follow?
The calculator is based on TAPPI T 441 standard, which is the international standard for determining water absorption (Cobb test) in paper, cardboard and corrugated board.
How many samples can I calculate?
The calculator includes fields for up to 5 samples, automatically calculating the individual Cobb value for each one and the average of all samples.
What formats is it available in?
The calculator is available in Excel format (.xlsx) to facilitate its use on computers. It is available in Spanish, English and Portuguese.
Can I share the calculator with my team?
Yes, once downloaded you can share the calculator with your work team. However, we recommend that each interested person register to receive future updates.
Related Resources
Explore more content about the Cobb test and water barrier coatings.
Complete Cobb test guide
Learn everything about how to perform the Cobb test step by step according to TAPPI T 441 standard.
Ready to professionalize your Cobb tests?
Download our free calculator and improve the accuracy and efficiency of your water resistance measurements.