Testers & scales calibrated before despatch

Gem & precious metal testers, since 1986

Magnification calculator

This is an Excel Document, so you will have to click OPEN after downloading the file. Enter the magnification to find the working distance, or enter the working distance to find the magnification. Works for all simple lenses (not microscopes and telescopes, and not surgeon's-type magnifiers (they are made of two little telescopes).