To determine your ring size:

Download the resizer document.

If, after using the sizing chart, you are still uncertain of your size, then visit your local jeweller for a more exact measurement.

The below chart may be useful but is for demonstration purposes.

47.4mm

48.7mm

50.0mm

51.3mm

52.5mm

53.7mm

55.0mm

56.2mm

57.5mm

58.8mm

60.0mm

61.3mm

62.5mm

63.8mm

65.0mm

66.3mm

67.5mm

68.8mm

70.0mm