Praktiskt

Percent Error Calculator

Experimental (measured) value

Theoretical (accepted) value

🌐

Detailed Guide Coming Soon

We're working on a comprehensive educational guide for the Percent Error Calculator in your language. The content below is shown in English.

Vad är Percent Error Calculator?

▾

Percent error measures the accuracy of an experimental or measured value compared to an accepted or theoretical value. It expresses the discrepancy as a percentage, making it easy to compare errors across different scales and units.

Calkulon makes complex calculations simple — built for students and everyday problem-solvers.

Hur man Percent Error Calculator

▾

1Percent error = |Experimental − Theoretical| / |Theoretical| × 100%
2The absolute value removes the sign — percent error is always positive
3Signed percent error indicates direction: positive = measured too high, negative = too low
4Used in chemistry, physics, engineering, and manufacturing quality control

Lösta exempel

▾

Exempel 1

Givet:Measured density: 9.7 g/cm³, True density: 10.0 g/cm³

Resultat:3.0% error

|9.7−10| / 10 × 100 = 3%

Exempel 2

Givet:Predicted 50, actual 47

Resultat:6.0% error

|50−47| / 47 × 100 = 6.38%

Acceptable Percent Error by Application

▾

Field	Typical acceptable error	Notes
Pharmaceutical manufacturing	<1%	Active ingredient content
Engineering / machining	<0.1–2%	Depends on tolerance
Chemical lab experiments	<5%	Educational context
Survey / opinion polls	±3–5%	Sampling error
Medical diagnostics	<5%	Varies by test type
Weather forecasting (24hr)	<10%	Temperature predictions

💡

Proffstips

Percent error uses the theoretical (accepted) value in the denominator, not the experimental value. Using the wrong denominator is a common mistake that gives a different — and incorrect — result.

⭐

Visste du?

NASA's Mars Climate Orbiter was lost in 1999 due to a unit conversion error — one team used metric units while another used imperial. The spacecraft was $327 million. The percent error in trajectory was small, but catastrophic at interplanetary scale.

Referenser

›Approximation error — Wikipedia

Formula-verified for precision

Reviewed October 2026

Our methodology

Ratings & comments

…

Få mattetips varje vecka

Gå med 12 000+ prenumeranter som får räknartips varje vecka.

🔒

100% Gratis

Ingen registrering

✓

Korrekt

Verifierade formler

⚡

Omedelbar

Resultat direkt

📱

Mobilanpassad

Alla enheter

Percent Error Calculator