Calculate image distance, object distance, or focal length using the thin lens equation. This calculator applies the Gaussian lens formula for converging and diverging lenses in paraxial approximation.
Enter your values below
Negative value per sign convention for real objects.
Leave blank to solve for image distance.
Leave blank to solve for focal length.
How this calculator works
The thin lens equation relates focal length f, image distance v, and object distance u. Convention: u is negative for real objects, v is positive for real images.
Common questions about this calculator
These calculators are for educational and informational purposes only. While we strive for accuracy, results should be verified for critical applications. Always consult authoritative sources for engineering or scientific work.
