Free Optical Calculators
Professional-grade tools for opticians. Calculate transpositions, reading powers, computer glasses, vertex distance, prism, and more—instantly and accurately.
Most Popular Calculators
The tools opticians use every day
Rx Transposition Calculator
Instantly convert prescriptions between plus and minus cylinder formats. Essential for every optician.
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Reading Glasses Power Calculator
Calculate the right reading add power based on age, working distance, and existing prescription.
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Computer Glasses Calculator
Convert reading add to intermediate power for computer use. Calculate the ideal add for any screen distance.
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Vertex Distance Compensation
Compensate high prescriptions for changes in vertex distance. Critical for contact lens conversions.
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Progressive Lens Identifier
Identify progressive lens brands and designs using manufacturer engravings. Decode the hidden markings.
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Lens Cutout Calculator
Check if a lens will cut out before ordering. Enter frame, PD, and blank size to verify fit.
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Rx Transposition Calculator
Instantly convert prescriptions between plus and minus cylinder formats. Essential for every optician.
Reading Glasses Power Calculator
Calculate the right reading add power based on age, working distance, and existing prescription.
Computer Glasses Calculator
Convert reading add to intermediate power for computer use. Calculate the ideal add for any screen distance.
Vertex Distance Compensation
Compensate high prescriptions for changes in vertex distance. Critical for contact lens conversions.
Progressive Lens Identifier
Identify progressive lens brands and designs using manufacturer engravings. Decode the hidden markings.
Layout Chart Generator
Generate professional lens layout charts for the lab. Visualize optical centers, seg heights, and more.
Prism Calculator (Prentice Rule)
Calculate induced prism from decentration or required decentration for prescribed prism.
Lens Thickness Estimator
Estimate edge and center thickness based on prescription, lens material, and frame size.
Lens Cutout Calculator
Check if a lens will cut out before ordering. Enter frame, PD, and blank size to verify fit.
Spectacle Magnification Calculator
Calculate the magnification or minification effect of spectacle lenses for aniseikonia concerns.
Spherical Equivalent Calculator
Convert sphero-cylindrical prescriptions to spherical equivalent for contact lens fitting and comparisons.
Why Opticians Trust Our Calculators
Instant Results
No waiting, no page reloads. Get answers in real-time.
Verified Formulas
Industry-standard calculations used by professionals.
Mobile-Friendly
Use on any device—phone, tablet, or computer.
Learn As You Go
See formulas and steps to understand the math.
Want to Master These Calculations?
Go beyond the calculator. Practice problems and learn the formulas for the ABO exam.