Decimal Equivalents for Drill Sizes

inch decimal equivalents
metric sizes
fractional sizes
number sizes
letter sizes

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Decimal Equivalents from # 80 to 1", .0135" to 1.000"

Drill	Decimal		Drill	Decimal		Drill	Decimal		Drill	Decimal		Drill	Decimal
80	.0135"		70	.0280"		60	.0400"		51	.0670"		3/32	.0938"
79	.0145"		69	.0292"		59	.0410"		50	.0700"		41	.0960"
1/64	.0156"		68	.0310"		58	.0420"		49	.0730"		40	.0980"
78	.0160"		1/32	.0313"		57	.0430"		48	.0760"		39	.0995"
77	.0180"		67	.0320"		56	.0465"		5/64	.0781"		38	.1015"
76	.0200"		66	.0330"		3/64	.0469"		47	.0785"		37	.1040"
75	.0210"		65	.0350"		55	.0520"		46	.0810"		36	.1065"
74	.0225"		64	.0360"		54	.0550"		45	.0820"		7/64	.1094"
73	.0240"		63	.0370"		53	.0595"		44	.0860"		35	.1100"
72	.0250"		62	.0380"		1/16	.0625"		43	.0890"		34	.1110"
71	.0260"		61	.0390"		52	.0635"		42	.0935"		33	.1130"

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

32

.1160"

23

.1540"

14

.1820"

5

.2055"

E

.2500"

31

.1200"

5/32

.1562"

13

.1850"

4

.2090"

1/4

.2500"

1/8

.1250"

22

.1570"

3/16

.1875"

3

.2130"

F

.2570"

30

.1285"

21

.1590"

12

.1890"

7/32

.2188"

G

.2610"

29

.1360"

20

.1610"

11

.1910"

2

.2210"

17/64

.2656"

28

.1405"

19

.1660"

10

.1935"

1

.2280"

H

.2660"

9/64

.1406"

18

.1695"

9

.1960"

A

.2340"

I

.2720"

27

.1440"

11/64

.1719"

8

.1990"

15/64

.2344"

J

.2770"

26

.1470"

17

.1730"

7

.2010"

B

.2380"

K

.2810"

25

.1495"

16

.1770"

13/64

.2031"

C

.2420"

9/32

.2812"

24

.1520"

15

.1800"

6

.2040"

D

.2460"

L

.2900"

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

M

.2950"

23/64

.3594"

29/64

.4531"

41/64

.6406"

53/64

.8281"

19/64

.2969"

U

.3680"

15/32

.4688"

21/32

.6562"

27/32

.8438"

N

.3020"

3/8

.3750"

31/64

.4844"

43/64

.6719"

55/64

.8594"

5/16

.3125"

V

.3770"

1/2

.5000"

11/16

.6875"

7/8

.8750"

O

.3160"

W

.3860"

33/64

.5156"

45/64

.7031"

57/64

.8906"

P

.3230"

25/64

.3906"

17/32

.5313"

23/32

.7188"

29/32

.9062"

21/64

.3281"

X

.3970"

35/64

.5469"

47/64

.7344"

59/64

.9219"

Q

.3320"

Y

.4040"

9/16

.5625"

3/4

.7500"

15/16

.9375"

R

.3390"

13/32

.4062"

37/64

.5781"

49/64

.7656"

61/64

.9531"

11/32

.3438"

Z

.4130

19/32

.5938"

25/32

.7812"

31/32

.9688"

S

.3480"

27/64

.4219"

39/64

.6094"

51/64

.7969"

63/64

.9844"

T

.3580"

7/16

.4375"

5/8

.6250"

13/16

.8125"

1

1.000"

 

 

 

Millimeter Sizes

Decimal Equivalents

mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal
.35	.0138"		.90	.0354"		1.45	.0571"		2.00	.0787"		2.55	.1004"
.40	.0157"		.95	.0374"		1.50	.0591"		2.05	.0807"		2.60	.1024"
.45	.0177"		1.0	.0394"		1.55	.0610"		2.10	.0827"		2.65	.1043"
.50	.0197"		1.05	.0413"		1.60	.0630"		2.15	.0846"		2.70	.1063"
.55	.0217"		1.10	.0433"		1.65	.0650"		2.20	.0866"		2.75	.1083"
.60	.0236"		1.15	.0453"		1.70	.0669"		2.25	.0886''		2.80	.1102"
.65	.0256"		1.20	.0472"		1.75	.0689"		2.30	.0906"		2.85	.1142"
.70	.0276"		1.25	.0492"		1.80	.0709"		2.35	.0925"		2.90	.1181"
.75	.0295"		1.30	.0512"		1.85	.0728"		2.40	.0945"		3.00	.1181"
.80	.0315"		1.35	.0531"		1.90	.0748"		2.45	.0965"		3.10	.1220"
.85	.0335"		1.40	.0551"		1.95	.0768"		2.50	.0984"		3.20	.1260"

 

mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal
3.25	.1280"		4.1	.1614"		4.9	.1929"		5.75	.2264"		6.6	.2598"
3.30	.1299"		4.2	.1654"		5	.1969"		5.8	.2283"		6.7	.2638"
3.40	.1339"		4.25	.1673"		5.1	.2008"		5.9	.2323"		6.75	.2657"
3.50	.1378"		4.3	.1693"		5.2	.2047"		6	.2362"		6.8	.2677"
3.6	.1417"		4.4	.1732"		5.25	.2067"		6.1	.2402"		6.9	.2717"
3.7	.1457"		4.5	.1772"		5.3	.2087"		6.2	.2441"		7	.2756"
3.75	.1476"		4.6	.1811"		5.4	.2126"		6.25	.2461"		7.1	.2795"
3.8	.1496"		4.7	.1850"		5.5	.2165"		6.3	.2480"		7.2	.2835"
3.9	.1535"		4.75	.1870"		5.6	.2205"		6.4	.2520"		7.25	.2854"
4	.1575"		4.8	.1890"		5.7	.2244"		6.5	.2559"		7.3	.2874"

mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal		mm	Decimal
7.4	.2913"		8.25	.3248"		9.1	.3583"		9.9	.3898"		14.5	.5709"
7.5	.2953"		8.3	.3268"		9.2	.3622"		10	.3937"		15	.5906"
7.6	.2992"		8.4	.3307"		9.25	.3642"		10.5	.4134"		15.5	.6102"
7.7	.3031"		8.5	.3346"		9.3	.3661"		11	.4331"		16	.6229"
7.75	.3051"		8.6	.3386"		9.4	.3701"		11.5	.4528"		16.5	.6496"
7.8	.3071"		8.7	.3425"		9.5	.3740"		12	.4724"		17	.6693"
7.9	.3110"		8.75	.3445"		9.6	.3780"		12.5	.4921"		17.5	.6890"
8	.3150"		8.8	.3465"		9.7	.3819"		13	.5118"		18	.7087"
8.1	.3189"		8.9	.3504"		9.75	.3839"		13.5	.5315"		18.5	.7283"
8.2	.3228"		9	.3543"		9.8	.3858"		14	.5512"		19	.7480"

mm	Decimal		mm	Decimal		mm	Decimal
19.5	.7677"		21.5	.8465"		23.5	.9252"
20	.7874"		22	.8661"		24	.9449"
20.5	.8071"		22.5	.8858"		24.5	.9646"
21	.8268"		23	.9055"		25	.9843"

 

 

 

FRACTIONAL DECIMAL EQUIVALENTS
1/64	0.015625		17/64	0.265625		33/64	0.515625		49/64	0.765625
1/32	0.03125		9/32	0.28125		17/32	0.53125		25/32	0.78125
3/64	0.046875		19/64	0.296875		35/64	0.546875		51/64	0.796875
1/16	0.0625		5/16	0.3125		9/16	0.5625		13/16	0.8125
5/64	0.078125		21/64	0.328125		37/64	0.578125		53/64	0.828125
3/32	0.09375		11/32	0.34375		19/32	0.59375		27/32	0.84375
7/64	0.109375		23/64	0.359375		39/64	0.609375		55/64	0.859375
1/8	0.125		3/8	0.375		5/8	0.625		7/8	0.875
9/64	0.140625		25/64	0.390625		41/64	0.640625		57/64	0.890625
5/32	0.15625		13/32	0.40625		21/32	0.65625		29/32	0.90625
11/64	0.171875		27/64	0.421875		43/64	0.671875		59/64	0.921875
3/16	0.1875		7/16	0.4375		11/16	0.6875		15/16	0.9375
13/64	0.203125		29/64	0.453125		45/64	0.703125		61/64	0.953125
7/32	0.21875		15/32	0.46875		23/32	0.71875		31/32	0.96875
15/64	0.234375		31/64	0.484375		47/64	0.734375		63/64	0.984375
1/4	0.250		1/2	0.500		3/4	0.750		1	1.000

 

 

NUMBER DRILL SIZES
No.	Size of No. in Decimals	No.	Size of No. in Decimals	No.	Size of No. in Decimals	No.	Size of No. in Decimals
1	0.2280	21	0.1590	41	0.0960	61	0.0390
2	0.2210	22	0.1570	42	0.0935	62	0.0380
3	0.2130	23	0.1540	43	0.0890	63	0.0370
4	0.2090	24	0.1520	44	0.0860	64	0.0360
5	0.2055	25	0.1495	45	0.0820	65	0.0350
6	0.2040	26	0.1470	46	0.0810	66	0.0330
7	0.2010	27	0.1440	47	0.0785	67	0.0320
8	0.1990	28	0.1405	48	0.0760	68	0.0310
9	0.1960	29	0.1360	49	0.0730	69	0.02925
10	0.1935	30	0.1285	50	0.0700	70	0.0280
11	0.1910	31	0.1200	51	0.0670	71	0.0260
12	0.1890	32	0.1160	52	0.0635	72	0.0250
13	0.1850	33	0.1130	53	0.0595	73	0.0240
14	0.1820	34	0.1110	54	0.0550	74	0.0225
15	0.1800	35	0.1100	55	0.0520	75	0.0210
16	0.1770	36	0.1065	56	0.0465	76	0.0200
17	0.1730	37	0.1040	57	0.0430	77	0.0180
18	0.1695	38	0.1015	58	0.0420	78	0.0160
19	0.1660	39	0.0995	59	0.0410	79	0.0145
20	0.1610	40	0.0980	60	0.0400	80	0.0135

 

 

 

LETTER DRILL SIZE
A	0.234	N	0.302
B	0.238	O	0.316
C	0.242	P	0.323
D	0.246	Q	0.332
E	0.250	R	0.339
F	0.257	S	0.348
G	0.261	T	0.358
H	0.266	U	0.368
I	0.272	V	0.377
J	0.277	W	0.386
K	0.281	X	0.397
L	0.290	Y	0.404
M	0.295	Z	0.413

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