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Both calculators run independently — change the inputs on either side to compare results.

Fresnel Reflection Calculator

Calculate the percentage of light reflected at an optical interface for s- or p-polarization using the Fresnel equations. Indispensable for anti-reflection coating design, laser optics, and photography filter analysis.

Refractive Index 1

Refractive Index 2

Incident Angle (degrees)

Polarization

Fill in the required fields to see your result.

Optics

Lens Focal Length Calculator

Compute the focal length of any thick or thin lens from its refractive index, surface curvatures, and center thickness using the lensmaker's equation. Essential for optical designers, physics students, and DIY telescope builders.

Refractive Index of Lens Material

Radius of First Surface (cm)

Radius of Second Surface (cm)

Lens Thickness (cm)

Fill in the required fields to see your result.

Key differences

	Fresnel Reflection Calculator	Lens Focal Length Calculator
Category	Optics	Optics
Inputs required	4	4
Result	Reflectance (%)	Focal Length (cm)
What it does	Calculate the percentage of light reflected at an optical interface for s- or p-polarization using the Fresnel equations. Indispensable for anti-reflection coating design, laser optics, and photography filter analysis.	Compute the focal length of any thick or thin lens from its refractive index, surface curvatures, and center thickness using the lensmaker's equation. Essential for optical designers, physics students, and DIY telescope builders.