Use the thin-lens equation to find where the image forms, how big it is, whether it is real or virtual and the lens power in dioptres.
loading toolHow to use the lens calculator
- Type your numbers in the boxes (pick your currency or units if asked).
- The answer updates as you type: no button to press.
- Copy the result, or share it on WhatsApp with one tap.
Questions
Is my data private?
Yes. Everything happens inside your own browser: nothing you type or choose is uploaded to us or anyone else.
Is it free?
Completely free, with no sign-up, no watermark and no limit on how many times you use it. Light ads keep the site running.





























