Percent Error Calculator
Calculate the percent error between your measured and actual values using the formula:|Measured Value - Actual Value| / |Actual Value| × 100
Quick Examples
Result: 2.04% error
Result: 0.8% error
How to Use This Calculator
Step 1: Enter Your Values
- • Actual Value: The true, theoretical, or accepted value
- • Measured Value: Your experimental or observed value
- • Both values must be numbers (can include decimals)
Step 2: Get Results
- • Results appear automatically as you type
- • Percent error is calculated to 2 decimal places
- • Color-coded accuracy indicators help interpret results
Understanding Your Results
Excellent (0-5%)
Very high accuracy. Your measurement is very close to the true value.
Good (5-15%)
Acceptable accuracy for most applications. Consider sources of error.
Needs Improvement (>15%)
High error. Review measurement technique and equipment calibration.
The Percent Error Formula
This formula calculates the percentage difference between your measured (experimental) value and the actual (theoretical) value. The result tells you how accurate your measurement is.
Common Applications
Physics Labs
Measuring gravity, velocity, acceleration, and other physical constants.
Chemistry Experiments
Determining density, concentration, molecular weights, and reaction yields.
Engineering Testing
Quality control, material testing, and equipment calibration.
Medical Research
Validating new measurement techniques and equipment accuracy.
Educational Projects
Student lab reports, science fair projects, and coursework.
Quality Assurance
Manufacturing tolerance checks and process validation.
Learn More
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