About this site
A free tool for one job: helping you pick a reading glasses strength to try.
What it does
Reading Glasses Test shows a diopter chart at its true size on your screen and suggests a reading glasses strength. It also has a strength chart by age, a printable chart, and a calculator for prescriptions and computer distance. Everything runs in your browser. There is no account, and the site sells no glasses.
How the strength is worked out
The chart has eleven lines of print, from 19 point down to 6 point, labeled +3.50 to +1.00. The sizes follow the range used on the printed charts that readers brands publish, read from 14 inches. Those charts are not standardized, so treat the result as accurate to about half a diopter.
Screens differ in size, so the site asks you to match a bank card once. A standard card is 85.6 mm wide, which tells the page how large a millimeter is on your screen.
The strength by age combines the charts published by Foster Grant and Readers.com as read on 12 November 2026. The calculator uses standard optics: focus needed equals one divided by the distance in meters, and reading strength from a prescription is sphere plus ADD.
What it is not
It is not an eye exam and not medical advice. It cannot detect astigmatism, a difference between your eyes, or eye disease. See an eye doctor for regular exams and for any sudden change in vision.
Independence
The site is not affiliated with any glasses brand or retailer. Brands are named only as sources. It is free to use and paid for by advertising.
Corrections
If you spot a mistake, please get in touch.