Percent Error Calculator
Compare a measured (experimental) value against the true (theoretical) value to get the absolute error and percent error. Small percent error means your measurement is close to the accepted value.
#percent error#percentage error#experimental value#theoretical value#measurement accuracy
TheCalculators — Percent Error Calculator
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Percent Error
9.091%
Underestimate (measured low) · absolute error 1
- Experimental value
- 10
- Theoretical value
- 11
- Difference (obs − true)
- -1
- Absolute error
- 1
- Percent error
- 9.0909%
- Direction
- Underestimate (measured low)
- Accuracy (100% − error)
- 90.909%
- Relative error (fraction)
- 0.090909
Step-by-step solution
- 1Find the differenceobserved − true = 10 − 11 = -1
- 2Take the absolute error|-1| = 1
- 3Divide by the true value1 ÷ |11| = 0.090909
- 4Convert to percent0.090909 × 100 = 9.0909%
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Formula
% error = |experimental − theoretical| / |theoretical| × 100
Pro tips
- • Percent error is always reported as a positive (absolute) quantity.
- • Compare against a benchmark: lab work often targets < 5% error.
- • Sign of the raw difference tells you whether you over- or under-measured.
FAQ
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