Prentice’s Rule Calculator

This tool is intended for educational and dispensing support use.

Use Prentice’s Rule to solve for induced prism, lens power, or decentration.

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Calculation Setup

Summary Output

Enter values above, choose the quantity you want to solve for, and submit the form.

Prentice’s Rule

Prentice’s Rule relates lens power, decentration, and induced prism:

Where Δ is prism diopters, D is lens power in diopters, and c is decentration in millimeters.