Method 1: Using a String (or Strip of Paper)

What You Will Need: String or piece of paper, ruler, pen/pencil/marker.

Steps:

Wrap it around the base of your finger, with a string or strip of paper Make It A Snug Fit Without Being Too Tight

Use a pen/marker to mark on the string or paper were it has overlapped.

Using a ruler, measure from the start of the string or paper to where you made an indication.

Find out your ring size by using a clearing house to work with plant measurements.

Method 2: How to Use a Printable Ring Sizer

What You Will Need: Print, Paper and Scissors

Steps:

Locate the Ring Sizer Template And Print an Accredited Jeweler's Website

Cut along the sizer edge and wrap it around your finger as per directions on template.

Use the sizing on the template to read your ring size.

Method 3: A ring that fits well, ruler, or a ring size chart

What You Will Need: Print, Scissors and Paper

Steps:

Put the ring over a ruler or size-pleaser chart.

Find out the diameter of inside where you would get your knurled section in millimeters

Find the corresponding ring size: Enter your measurement in a rindsizer chart to get its equivalent ring-size.

Things to keep in mind for Accurate Measurement

Measure at the end of the Day: Because fingers till enlarge in their natural ways usually tend to be larger by eve / late afternoon than they are very first thing.

Adjust For Temperature: High temperatures can cause your fingers expand, while low ones may make them shrink.

Sadly, as weird and easy it is to measure fingers online, the rings are quite difficult because unlike in person they cannot be resized several times.

Size of Knuckle: If your knuckles are considerably bigger than the base of your finger, measure both and choose a size in between.