Home/Clothing & Sizing/Cm To Mm Ring Size Converter

Cm To Mm Ring Size Converter

Convert a ring circumference measurement from centimeters to millimeters and find the corresponding standard ring size.

Was this calculator helpful?

Share this Calculator

About the CM to MM Ring Size Converter

The "CM to MM Ring Size Converter" is a specialized tool designed to help you determine your US ring size from a measurement you can easily take at home. If you've measured your finger's circumference in centimeters (cm) using a string or a strip of paper, this calculator will convert it to millimeters (mm) and match it to the closest standard US ring size.

How Does the Calculator Work?

The functionality is based on a simple conversion and a lookup in a standard sizing chart.

The Formula and Logic

  1. Conversion from CM to MM: The calculator first converts your input from centimeters to millimeters. This is a straightforward metric conversion:
    Millimeters = Centimeters × 10
  2. Ring Size Matching: Once the circumference is in millimeters, the calculator compares this value to a standard US ring size chart. It finds the ring size whose millimeter circumference is mathematically closest to your measurement.

Practical Example

Let's walk through a real-world scenario.

  • Measurement: You wrap a piece of string around your finger, mark it, and measure it against a ruler. It measures 5.4 cm.
  • Input: You enter "5.4" into the calculator.
  • Conversion: The calculator computes 5.4 cm × 10 = 54.0 mm.
  • Matching: It then looks at the internal ring size chart. It finds that 54.4 mm corresponds to a US size 7. Since 54.0 mm is very close to 54.4 mm, the calculator suggests that your approximate ring size is 7.

How to Measure Your Finger at Home

  1. Take a piece of non-stretchy string or a thin strip of paper.
  2. Wrap it snugly around the base of the finger you want to measure. Make sure it can slide over your knuckle.
  3. Mark the point where the end overlaps.
  4. Lay the string or paper flat and measure the length from the start to the mark using a ruler with centimeter markings.
  5. Enter this measurement into the calculator.

Similar Calculators

Calculate the volume and capacity of a bag based on its dimensions, perfect for luggage, backpacks, and totes.

Find your perfect belt size by using your waist measurement. Get recommendations for both standard and vanity sizing.

Determine your bikini top and bottom size based on your bust, underbust, waist, and hip measurements for a perfect fit.

Find your accurate bra size with our easy-to-use calculator. Measure your band and bust size to get a comfortable and supportive fit.

Calculate the waist radius and fabric yardage needed to sew a full, half, or quarter circle skirt.

Find your US ring size by entering the circumference of your finger in centimeters. A useful tool for online jewelry shopping.

Determine the ideal number of curtain panels for your window to achieve the desired fullness and look.

Calculate the recommended length and width for your curtains based on your window size and desired style.

Explore Other Calculators

Calculate your car's 0-60 mph time based on its horsepower and weight.

Quickly calculate the date that is 100 days from a starting date. Perfect for tracking 100-day challenges or project milestones.

Estimate your self-employment taxes as a freelancer or independent contractor. Helps you plan for quarterly tax payments and avoid surprises.

Find the date that is 120 days from any given start date. Useful for planning timelines, loan terms, and long-term projects.

Calculate the date that is 180 days (about six months) from a specific start date. Ideal for setting semi-annual goals or deadlines.

A simple tool to find the date that is exactly 30 days from a given start date. Commonly used for trial periods and monthly planning.

Quickly add or subtract 30 minutes from any given time. A handy tool for scheduling meetings, breaks, or appointments.

Project the growth of your 401(k) retirement savings over time. See how contributions, employer match, and investment returns can impact your nest egg.