Percent Uncertainty Calculator (with Examples) - OneSDR

🎯 Measure Precision in Your Results

In science and engineering, measurements are never 100% exact. That’s where percent uncertainty comes in — it helps quantify how precise a measurement is.
Use our Percent Uncertainty Calculator to quickly determine the reliability of any measurement. 🧪📏

Table of Contents

🔢 Try the Percent Uncertainty Calculator

Enter the absolute uncertainty
Enter the measured value
Instantly see the percent uncertainty

Percent Uncertainty Calculator

⚙️ Percent Uncertainty Calculator

Uncertainty (±) Measured Value

📚 What Is Percent Uncertainty?

Percent uncertainty expresses the size of the uncertainty in a measurement as a percentage of the total measured value.

Formula

Percent Uncertainty = (Absolute Uncertainty ÷ Measured Value) × 100

Where:

Absolute Uncertainty is the possible error (e.g., ±0.2 cm)
Measured Value is the total measurement (e.g., 10.0 cm)

💡 Example

Let’s say you measured a length of 12.0 cm with an uncertainty of ±0.3 cm:

Percent Uncertainty = (0.3 ÷ 12.0) × 100 = 2.5%

👉 Your measurement has a 2.5% uncertainty.

🎯 Why Use This Calculator?

✅ Evaluate the reliability of lab measurements
✅ Compare instruments based on precision
✅ Standardize uncertainty across different units
✅ Use in physics, chemistry, biology, and engineering

✨ Final Tip

The lower the percent uncertainty, the more reliable your measurement is.
Great for students, lab reports, researchers, and anyone who works with data!