Size Conversions for Caps and Rings

Cap Sizes

Scroll down for ring sizes and gold guide and other useful info.

American Sizes
Mens Head Measurement

in inches

Ladies' Head Measurement

in inches

Metric Sizes
.
.
.
48
6 1/8
.
.
49
6 1/4
.
.
50
6 3/8
20 1/2
19 1/2
51
6 1/2
20 5/8
20
52
6 5/8
21
20 1/2
53
6 3/4
21 1/2
21
54
6 7/8
21 7/8
21 1/2
55
7
22 1/4
22
56
7 1/8
22 5/8
22 1/8
57
7 1/4
23
23
58
7 3/8
23 3/8
23 1/2
59
7 1/2
23 3/4
24
60
7 5/8
24
24 1/2
61
7 3/4
24 1/2
25
62
7 7/8
25
25 1/2
63
8
25 1/2
26
64

How do I know the right hat size?

Got a tape measure handy?
Step 1: Measure your head with a tape measure, fitting it comfortably about one inch above your ears, or you can mark off a piece of string and measure it.
Step 2: Write it down for future reference.
Step 3: Use the chart that converts inches to hat sizes, both True Fit (1/8 hat size) and Easy Fit (S, M, L, and XL).



Adult Hat Sizing Chart

XS S M L XL XXL XXXL
Size
6 1/2
6 5/8
6 3/4
6 7/8
7
7 1/8
7 1/4
7 3/8
7 1/2
7 5/8
7 3/4
7 7/8
8
Inches
20 1/2
20 3/4
21 1/8
21 1/2
21 7/8
22 1/4
22 5/8
23
23 1/2
23 7/8
24 1/4
24 5/8
25
Metric
52
53
54
55
56
57
58
59
60
61
62
63
64

Children's Hat Sizing Chart

Size

S

M

L

XL

Hat Size

6 1/8

6 1/4

6 3/8

6 1/2

6 5/8

6 3/4

6 7/8

Inches

19 1/8

19 1/2

20

20 1/4

20 3/4

21 1/2

21 3/4

Metric

49

50

51

52

53

54

55

Ring Sizes

Inside Inside Inside Inside Number Sizes Wheat Sheaf    
Diameter Diameter Circumference Circumference US/Canada British Japanese Swiss
(inches) (mm) (inches) (mm) Standard Irish Equivalent Equivalent
       

 

Australian    
          Equivalent    
0.458 11.6 1.438 36.5 0      
0.466 11.8 1.463 37.2 1/4      
0.474 12.0 1.488 37.8 1/2 A    
0.482 12.2 1.513 38.4 3/4 A 1/2    
0.490 12.4 1.539 39.1 1 B 1  
0.498 12.6 1.564 39.7 1 1/4 B 1/2    
0.506 12.9 1.589 40.4 1 1/2 C    
0.514 13.1 1.614 41.0 1 3/4 C 1/2    
0.522 13.3 1.639 41.6 2 D 2 1.50
0.530 13.5 1.664 42.3 2 1/4 D 1/2    
0.538 13.7 1.689 42.9 2 1/2 E 3 2.75
0.546 13.9 1.714 43.5 2 3/4 E 1/2    
0.554 14.1 1.740 44.2 3 F 4 4.00
0.562 14.3 1.765 44.8 3 1/4 F 1/2 5 5.25
0.570 14.5 1.790 45.5 3 1/2 G    
0.578 14.7 1.815 46.1 3 3/4 G 1/2 6 6.50
0.586 14.9 1.840 46.7 4 7  
0.594 15.1 1.865 47.4 4 1/4 H 1/2   7.75
0.602 15.3 1.890 48.0 4 1/2 8  
0.610 15.5 1.915 48.7 4 3/4 J   9.00
0.618 15.7 1.941 49.3 5 J 1/2 9  
0.626 15.9 1.966 49.9 5 1/4 K   10.00
0.634 16.1 1.991 50.6 5 1/2 K 1/2 10  
0.642 16.3 2.016 51.2 5 3/4 L   11.75
0.650 16.5 2.041 51.8 6 L 1/2 11 12.75
0.658 16.7 2.066 52.5 6 1/4 12  
0.666 16.9 2.091 53.1 6 1/2 M 1/2 13 14.00
0.674 17.1 2.116 53.8 6 3/4 N    
0.682 17.3 2.141 54.4 7 N 1/2 14 15.25
0.690 17.5 2.167 55.0 7 1/4    
0.698 17.7 2.192 55.7 7 1/2 O 1/2 15 16.50
0.706 17.9 2.217 56.3 7 3/4    
0.714 18.1 2.242 56.9 8 P 1/2 16 17.75
0.722 18.3 2.267 57.6 8 1/4    
0.730 18.5 2.292 58.2 8 1/2 Q 1/2 17  
0.738 18.7 2.317 58.9 8 3/4 R   19
0.746 18.9 2.342 59.5 9 R 1/2 18  
0.754 19.2 2.368 60.1 9 1/4 S   20.25
0.762 19.4 2.393 60.8 9 1/2 S 1/2 19  
0.770 19.6 2.418 61.4 9 3/4 T   21.5
0.778 19.8 2.443 62.1 10 T 1/2 20  
0.786 20.0 2.468 62.7 10 1/4 U 21  
0.794 20.2 2.493 63.3 10 1/2 U 1/2 22 22.75
0.802 20.4 2.518 64.0 10 3/4 V    
0.810 20.6 2.543 64.6 11 V 1/2 23  
0.818 20.8 2.569 65.2 11 1/4 W   25
0.826 21.0 2.594 65.9 11 1/2 W 1/2 24  
0.834 21.2 2.619 66.5 11 3/4 X    
0.842 21.4 2.644 67.2 12 X 1/2 25 27.50
0.850 21.6 2.669 67.8 12 1/4    
0.858 21.8 2.694 68.4 12 1/2 Z 26 28.75
0.866 22.0 2.719 69.1 12 3/4 Z 1/2    
0.874 22.2 2.744 69.7 13   27  
0.882 22.4 2.769 70.3 13 1/4 Z1    
0.890 22.6 2.795 71.0 13 1/2      
0.898 22.8 2.820 71.6 13 3/4 Z2    
0.906 23.0 2.845 72.3 14 Z3    
0.914 23.2 2.870 72.9 14 1/4      
0.922 23.4 2.895 73.5 14 1/2 Z4    
0.930 23.6 2.920 74.2 14 3/4      
0.938 23.8 2.945 74.8 15      
0.946 24.0 2.970 75.4 15 1/4      
0.954 24.2 2.996 76.1 15 1/2      
0.962 24.4 3.021 76.7 15 3/4      
0.970 24.6 3.046 77.4 16      

Make sure when you print the ring sizer picture, you keep it its original size.


GOLD KARAT INFORMATION CHART

Karat Gold Parts Gold Percentage Gold Normal European Stamping
9 kt 9 in 24 37.50% 375
10 kt 10 in 24 41.67% 416
12 kt 12 in 24 50% 500
14 kt 14 in 24 58.33% 583 or 585
18 kt 18 in 24 75% 750
22 kt 22 in 24 91.67% 917
24 kt 24 in 24 99.99% 999 or .99999

Gold (K= karat) (P= Plum) Plum is high quality (purity) when a P is added. (example 18KP)

10K......41.7%pure

12K......50% pure

14K......58.3% pure

18K......75% pure

22K......91.2% pure

24K......99.9% pure

Gold Filled Markings (W1/20 14K G.F.) what it means: W=weight,

1/20 = 5% gold, G.F. = Gold Filled. Gold Filled is 300 times
thicker than gold plating. Gold filled is bonded to brass or bronze with
(fusing) heat & pressure. By law 5% of its total weight must be gold.

Gold Plating:
Thin coating of gold over a base metal (Electroplating) A gold plated
item will be marked 18K or 14K HGE (Heavy Gold Electroplating)
Gold plating is 7 - 100 millionths of an inch thick.

Silver:

Sterling is 92.5% silver, 7.5% copper

Sterling Markings are .925, STER, STERLING.

Sterling from England are marked by a Lion Hallmark.

Silver Filled items are marked 1/20 silver filled.

Vermeil is sterling silver covered by an electroplating of gold.

Platinum:

Markings are PLAT, or PLATINUM, and maybe marked .900 or .950

 

Troy Pound (0.37kg)
A mass unit is used to measure precious metals. There are 12 troy ounces in every troy pound. One troy pound is equal to 373 grams.

Troy Ounce
The traditional unit of weight for precious metals and gems.
1 troy ounce = 480 grains
1 troy ounce = 24 scruples
1 troy ounce = 20 pennyweights (North American jewelery trade)
1 troy ounce = 1.097 ordinary ounce
1 troy ounce = 8 drams
1 troy ounce = 31.1034768 grams.
1 troy ounce = 120 carats
1 troy ounce = 155.52 metric carats (diamonds / precious stones).
3.75 troy ounces = 10 tolas (Indian sub-continent)
6.02 troy ounces = 5 taels (Hong Kong)
12 troy ounce=1 troy pound
14.583 troy ounce =16 avoirdupois ounce (1Pound)
32.15 troy ounces = 1 kilogramme (Kilo)
32,150 troy ounces = 1 metric ton (1,000 kilos)
1000 troy ounces = 31.1 kilograms Pennyweight (dwt):
The pennyweight was the weight of a silver penny in medieval England.
It is no coincidence that there were 240 pennies to the English pound.
240 silver pennies were equivalent to a pound of silver.
The word sterling applies both to the English pound and to the standard
purity of silver.
1 pennyweight = 24 grains (dwt) (1 old time French penny)
1.55 grams=1 pennyweight (dwt)
20 dwt=1 troy ounce
240 pennyweights = 1 pound troy
24 grains=1 dwt
1 pennyweight =.05 troy ounce
1 gram=.643 pennyweight

Gram
1 gram =.03215 troy ounce
1 gram =.643 pennyweight
1.555 grams = 1 pennyweight (dwt)
1 gram =0.00267923 apothecary or troy pound
1 gram =0.00220462 avoirdupois pound
1 gram =0.0321507 apothecary or troy ounce
1 gram =0.564383 avoirdupois dram
1 gram =0.257206 apothecary or troy dram
1 gram =0.6430149 pennyweight
1 gram =0.771618 scruple
1 gram =15.4324 grains
1 gram =1x10^-6 metric ton
1 gram =1x10^-4 myriagram
1 gram =0.001 kilogram
1 gram =5 metric carats
1 gram =1000 milligrams
1 gram =1x10^6 microgram
1 Gram = 5 Carats

Gram-Calorie (mean)
Gram-Calorie (mean) =1.5593x10^-6 horse power hours
Gram-Calorie (mean) =0.001 kilogram calorie
Gram-Calorie (mean) = 0.0011628 watt-hour
Gram-Calorie (mean) =0.001459 cubic foot atmosphere
Gram-Calorie (mean) =0.0039685 BTU (mean)
Gram-Calorie (mean) =0.0039685 BTU (mean)
Gram-Calorie (mean) =0.041311 liter-atmosphere
Gram-Calorie (mean) =0.42685 kilogram-meter
Gram-Calorie (mean) =3.0874 foot-pounds
Gram-Calorie (mean) =4.186 joules (absolute)
Gram-Calorie (mean) =99.334 foot-poundals
Gram-calorie (15°C) = 4.185 joules (absolute).
Gram-calorie (20°C) = 4.181 joules (absolute).
Gram-centimeter =2.3427x10^-8 kilogram-calorie (mean)
Gram-centimeter =9.2972x10^-8 BTU (mean)
Gram-centimeter =1x10^-5 kilogram-meter
Gram-centimeter =2.3427x10^-5 gram-calorie (mean)
Gram-centimeter =7.233x10^-5 foot-pound
Gram-centimeter =9.80665x10^-5 joule (absolute)
Gram-centimeter =980.7 ergs


Grain:
An ancient unit which was originally based on the weight of a grain of wheat. The grain is the smallest unit of weight in the avoirdupois, troy, and apothecaries systems. Surprisingly it is identical in all three systems.
1 grain = 64.8 milligrams
1 grain = 0.0648 grams
4 grains = 1 carat
15.432 grains = 1 gram
20 grains = 1 scruple
24 grains =1 pennyweight
480 grains = 1 troy ounce
5760 grains = 1 troy pound
437.5 grains = 1 ounce avoirdupois
7000 grains = 1 pound avoirdupois
Grain = 1/7000 avoirdupois pound
Grain = 1/5760 apothecary or troy pound
Grain = 0.0022857 avoirdupois ounce
Grain = 0.0020833 apothecary or troy ounce
Grain = 0.03657143 avoirdupois dram
Grain = 0.016667 apothecary or troy dram
Grain = 0.0416667 troy pennyweight
Grain = 0.05000 apothecary scruple
Grain =0.064798918 gram
Grain =0.3240 metric carat
Grain =64.798918 milligram


Dram or Drachm
An ancient unit of weight, also a Greek coin. It is believed to have originally meant the amount which one could hold in one's hand.
16 drams = 1 ounce avoirdupois
8 drams = 1 ounce apothecaries
1 drams = 27.34375 grains
1 dram = 1.772 grams
3 scruples = 1 drachm
20 grains = 1 scruple


Momme
A unit of weight previously used in Japan to weigh pearls.
75 grains = momme
18.75 carats = 1 momme
3.75 grams = 1 momme

Imperial System
A British system developed and refined from the earlier Roman systems used in Britain during the middle ages.
Kevin Loughrey from Non Volatile Technologies Pty Ltd contributed some corrections below.
20 cwt = 1 ton (40 bushells or 160 stones) = 1 ton avoirdupois
4 stones = 1 bushell (56lbs)
1 hundredweight (cwt) = 112lbs (2 bushells, or 8 stones)
14 pounds avoirdupois = 1 stone avoirdupois
16 ounces avoirdupois = 1 pound avoirdupois
1 ounce avoirdupois = 28.349523 grams approx.
1 pound avoirdupois = 453.59237 grams
1 ton avoirdupois = 2240 pounds avoirdupois


Conversion Formulas
Use these formulas to convert!
Carats to Dwt x by .12860
Carats to Grams x by .2
Dwt to Carats x by 7.776
Dwt to Grams x by 1.5552
Dwt to Troy oz x by .05
Grams to Carats x by 5.0
Grams to Dwt x by .64301
Avoir Oz to Troy oz x by .91146
Avoir Oz to Grams x by 28.3495
Troy Oz to Avoir oz x by 1.091


Convert fractions to decimals and millimeters and reverse.
(1 INCH = 25.4 MM EXACTLY)

fraction decimal mm fraction decimal mm fraction decimal mm
1/64 0.0156 0.3969 1 1/64 1.0156 25.7969 2 1/64 2.0156 51.1969
1/32 0.0313 0.7938 1 1/32 1.0313 26.1938 2 1/32 2.0313 51.5938
3/64 0.0469 1.1906 1 3/64 1.0469 26.5906 2 3/64 2.0469 51.9906
1/16 0.0625 1.5875 1 1/16 1.0625 26.9875 2 1/16 2.0625 52.3875
5/64 0.0781 1.9844 1 5/64 1.0781 27.3844 2 5/64 2.0781 52.7844
3/32 0.0938 2.3813 1 3/32 1.0938 27.7813 2 3/32 2.0938 53.1813
7/64 0.1094 2.7781 1 7/64 1.1094 28.1781 2 7/64 2.1094 53.5781
1/8 0.1250 3.1750 1 1/8 1.1250 28.5750 2 1/8 2.1250 53.9750
9/64 0.1406 3.5719 1 9/64 1.1406 28.9719 2 9/64 2.1406 54.3719
5/32 0.1563 3.9688 1 5/32 1.1563 29.3688 2 5/32 2.1563 54.7688
11/64 0.1719 4.3656 1 11/64 1.1719 29.7656 2 11/64 2.1719 55.1656
3/16 0.1875 4.7625 1 3/16 1.1875 30.1625 2 3/16 2.1875 55.5625
13/64 0.2031 5.1594 1 13/64 1.2031 30.5594 2 13/64 2.2031 55.9594
7/32 0.2188 5.5563 1 7/32 1.2188 30.9563 2 7/32 2.2188 56.3563
15/64 0.2344 5.9531 1 15/64 1.2344 31.3531 2 15/64 2.2344 56.7531
1/4 0.2500 6.3500 1 1/4 1.2500 31.7500 2 1/4 2.2500 57.1500
17/64 0.2656 6.7469 1 17/64 1.2656 32.1469 2 17/64 2.2656 57.5469
9/32 0.2813 7.1438 1 9/32 1.2813 32.5438 2 9/32 2.2813 57.9438
19/64 0.2969 7.5406 1 19/64 1.2969 32.9406 2 19/64 2.2969 58.3406
5/16 0.3125 7.9375 1 5/16 1.3125 33.3375 2 5/16 2.3125 58.7375
21/64 0.3281 8.3344 1 21/64 1.3281 33.7344 2 21/64 2.3281 59.1344
11/32 0.3438 8.7313 1 11/32 1.3438 34.1313 2 11/32 2.3438 59.5313
23/64 0.3594 9.1281 1 23/64 1.3594 34.5281 2 23/64 2.3594 59.9281
3/8 0.3750 9.5250 1 3/8 1.3750 34.9250 2 3/8 2.3750 60.3250
25/64 0.3906 9.9219 1 25/64 1.3906 35.3219 2 25/64 2.3906 60.7219
13/32 0.4063 10.3188 1 13/32 1.4063 35.7188 2 13/32 2.4063 61.1188
27/64 0.4219 10.7156 1 27/64 1.4219 36.1156 2 27/64 2.4219 61.5156
7/16 0.4375 11.1125 1 7/16 1.4375 36.5125 2 7/16 2.4375 61.9125
29/64 0.4531 11.5094 1 29/64 1.4531 36.9094 2 29/64 2.4531 62.3094
15/32 0.4688 11.9063 1 15/32 1.4688 37.3063 2 15/32 2.4688 62.7063
31/64 0.4844 12.3031 1 31/64 1.4844 37.7031 2 31/64 2.4844 63.1031
1/2 0.5000 12.7000 1 1/2 1.5000 38.1000 2 1/2 2.5000 63.5000
33/64 0.5156 13.0969 1 33/64 1.5156 38.4969 2 33/64 2.5156 63.8969
17/32 0.5313 13.4938 1 17/32 1.5313 38.8938 2 17/32 2.5313 64.2938
35/64 0.5469 13.8906 1 35/64 1.5469 39.2906 2 35/64 2.5469 64.6906
9/16 0.5625 14.2875 1 9/16 1.5625 39.6875 2 9/16 2.5625 65.0875
37/64 0.5781 14.6844 1 37/64 1.5781 40.0844 2 37/64 2.5781 65.4844
19/32 0.5938 15.0813 1 19/32 1.5938 40.4813 2 19/32 2.5938 65.8813
39/64 0.6094 15.4781 1 39/64 1.6094 40.8781 2 39/64 2.6094 66.2781
5/8 0.6250 15.8750 1 5/8 1.6250 41.2750 2 5/8 2.6250 66.6750
41/64 0.6406 16.2719 1 41/64 1.6406 41.6719 2 41/64 2.6406 67.0719
21/32 0.6563 16.6688 1 21/32 1.6563 42.0688 2 21/32 2.6563 67.4688
43/64 0.6719 17.0656 1 43/64 1.6719 42.4656 2 43/64 2.6719 67.8656
11/16 0.6875 17.4625 1 11/16 1.6875 42.8625 2 11/16 2.6875 68.2625
45/64 0.7031 17.8594 1 45/64 1.7031 43.2594 2 45/64 2.7031 68.6594
23/32 0.7188 18.2563 1 23/32 1.7188 43.6563 2 23/32 2.7188 69.0563
47/64 0.7344 18.6531 1 47/64 1.7344 44.0531 2 47/64 2.7344 69.4531
3/4 0.7500 19.0500 1 3/4 1.7500 44.4500 2 3/4 2.7500 69.8500
49/64 0.7656 19.4469 1 49/64 1.7656 44.8469 2 49/64 2.7656 70.2469
25/32 0.7813 19.8438 1 25/32 1.7813 45.2438 2 25/32 2.7813 70.6438
51/64 0.7969 20.2406 1 51/64 1.7969 45.6406 2 51/64 2.7969 71.0406
13/16 0.8125 20.6375 1 13/16 1.8125 46.0375 2 13/16 2.8125 71.4375
53/64 0.8281 21.0344 1 53/64 1.8281 46.4344 2 53/64 2.8281 71.8344
27/32 0.8438 21.4313 1 27/32 1.8438 46.8313 2 27/32 2.8438 72.2313
55/64 0.8594 21.8281 1 55/64 1.8594 47.2281 2 55/64 2.8594 72.6281
7/8 0.8750 22.2250 1 7/8 1.8750 47.6250 2 7/8 2.8750 73.0250
57/64 0.8906 22.6219 1 57/64 1.8906 48.0219 2 57/64 2.8906 73.4219
29/32 0.9063 23.0188 1 29/32 1.9063 48.4188 2 29/32 2.9063 73.8188
59/64 0.9219 23.4156 1 59/64 1.9219 48.8156 2 59/64 2.9219 74.2156
15/16 0.9375 23.8125 1 15/16 1.9375 49.2125 2 15/16 2.9375 74.6125
61/64 0.9531 24.2094 1 61/64 1.9531 49.6094 2 61/64 2.9531 75.0094
31/32 0.9688 24.6063 1 31/32 1.9688 50.0063 2 31/32 2.9688 75.4063
63/64 0.9844 25.0031 1 63/64 1.9844 50.4031 2 63/64 2.9844 75.8031
1 1.0000 25.4000 2 2.0000 50.8000 3 3.0000 76.2000

MORE USEFUL CONVERSIONS
To convert decimal fractions of an inch to fractions of an inch.


Take the decimal fraction of feet and divide by 0.08333 (1/12th) and this will give you inches and decimals of an inch.
For example - 6.37 feet. Take the 0.37 feet and divide by 0.0833 = 4.44 inches .
So for 6.37 ft. we can also say 6 ft. -  4.44 in.
Now take the 0.44 in. and round it down to 0.4 which is 4/10"
We can now say 6.37' approximatly equals 6' - 4 4/10"

For fractions of an inch other than tenth's, take the decimal remainder of inches and divide by:
0.125 for the number of eighth's
0.0625 for the number of sixteenth's
0.03125 for the number of thirty-second's
0.015625 for the number of sixty-fourth's, and so on.

For example - 4.382 inches. For eighth's, divide the remainder, 0.382 by 0.125 and the answer is 3.056 so the fraction is a bit over 3 eighth's, therefore the answer ends up as approx. 4 3/8"