Gear Diametral Pitch, Module Conversion Table Chart

Gear Application and Design Resources

The following charts convert gear pitch dimensional data to the following:

Diametral Pitch, Module, Circular Pitch

Module: is the unit of size that indicates how big or small a gear is. It is the ratio of the reference diameter of the gear divided by the number of teeth.

Module = (Reference Diameter) / (Number of Teeth)
m = d / z

Diametric, module and circular pitches Conversion.

Diametral Pitch	Circular Pitch in Inches	Circular Pitch in Millimeters	Module In Millimeters
20 24 25.3995 31.4159 31.7653 32 36.2857 42.3333 48 50.8348 63.5950 64 72 80 84.6198 96 101.6697 120 127.1899 200	.1571 .1309 .1237 .100 .0989 .0982 .0856 .0742 .0654 .0618 .0494 .0491 .0436 .0393 .0371 .0327 .0309 .0262 .0247 .0157	3.990 3.325 3.142 2.540 2.513 2.494 2.199 1.885 1.661 1.571 1.256 1.247 1.107 .998 .943 .831 .785 .665 .628 .399	1.2700 1.0583 1.0 .8085 .8 .7938 .7 .6 .5288 .5 .4 .3969 .3524 .3177 .3 .2645 .25 .2116 .2 .127

Standard Stock Pitches	Addendum	Dedendum	Whole Depth	Circular Pitch
20 24 1/10 32 48 64 72 80 96 120 200	.0500 .0417 .0318 .0313 .0208 .0156 .0139 .0125 .0104 .0083 .0050	.0579 .0520 .0402 .0395 .0270 .0208 .0187 .0170 .0145 .0120 .0080	.1079 .0937 .0720 .0708 .0478 .0364 .0326 .0295 .0249 .0203 .0130	.1571 .1309 .1000 .0982 .0654 .0491 .0436 .0393 .0327 .0262 .0157

Diametral Pitch (inch)	Circular Pitch (inch)	Module
0.3387	9.2764	75
0.3629	8.658	70
0.3908	8.0395	65
0.4233	7.4211	60
0.4618	6.8027	55
0.5	6.2832	50.8
0.508	6.1843	50
0.5644	5.5658	45
0.6048	5.1948	42
0.6513	4.8237	39
0.7056	4.4527	36
0.75	4.1888	33.867
0.7697	4.0816	33
0.7854	4	12.128
0.8467	3.7106	30
0.8976	3.5	12
0.9407	3.3395	27
1	3.1416	25.4
1.0472	3	11.622
1.0583	2.9684	24
1.1424	2.75	11.289
1.1545	2.7211	22
1.25	2.5133	20.32
1.2566	2.5	11.117
1.27	2.4737	20
1.3963	2.25	11
1.4111	2.2263	18
1.5	2.0944	16.933
1.5708	2	10.612
1.5875	1.979	16
1.6755	1.875	10.16
1.6933	1.8553	15
1.75	1.7952	14.514
1.7952	1.75	10
1.8143	1.7316	14
1.9333	1.625	9.236
1.9538	1.6079	13
2	1.5708	12.7
2.0944	1.5	9.096
2.1167	1.4842	12
2.1855	1.4375	9
2.25	1.3963	11.289
2.2848	1.375	8.59
2.3091	1.3605	11
2.3936	1.3125	8.467
2.5	1.2566	10.16
2.54	1.2369	10
2.75	1.1424	9.236
2.7925	1.125	8.085
2.8222	1.1132	9
2.9568	1.0625	8
3	1.0472	8.467
3.1416	1	7.58
3.175	0.9895	8
3.351	0.9375	7.257
3.5	0.8976	7.257
3.5904	0.875	7.074
3.6286	0.8658	7
3.8666	0.8125	7
3.9077	0.804	6.5
4	0.7854	6.35
4.1888	0.75	6.569
4.2333	0.7421	6
4.5	0.6981	5.644
4.5696	0.6875	6.5
4.6182	0.6803	5.5
4.71	0.667	6.35
5	0.6283	5.08
5.0266	0.625	6.064
5.08	0.6184	5
5.5851	0.5625	6
5.6444	0.5566	4.5
6	0.5236	4.233
6.2832	0.5	5.644
6.35	0.4947	4
6.7733	0.4638	3.75
7	0.4488	3.629
7.1808	0.4375	5.558
7.2571	0.4329	3.5
7.8154	0.402	3.25
7.854	0.4	5.5
8	0.3927	3.175
8.3776	0.375	5.393
8.4667	0.3711	3
9	0.3491	2.822
9.2364	0.3401	2.75
9.4342	0.333	5.08
10	0.3142	2.54
10.0531	0.3125	5.053
10.16	0.3092	2.5
10.9846	0.286	5
11	0.2856	2.309
11.2889	0.2783	2.25
12	0.2618	2.117
12.5664	0.25	4.548
12.7	0.2474	2
13	0.2417	1.954
14	0.2244	1.814
14.1514	0.222	4.5
14.5143	0.2164	1.75
15	0.2094	1.693
15.708	0.2	4.233
16	0.1964	1.588
16.7552	0.1875	4.043
16.9333	0.1855	1.5
17	0.1848	1.494
18	0.1745	1.411
18.812	0.167	4
19	0.1653	1.337
20	0.1571	1.27
20.32	0.1546	1.25
22	0.1428	1.155
24	0.1309	1.058
25.4	0.1237	1
26	0.1208	0.977
28	0.1122	0.907
28.2222	0.1113	0.9
30	0.1047	0.847
31.75	0.0989	0.8
32	0.0982	0.794
34	0.0924	0.747
36	0.0873	0.706
36.2857	0.0866	0.7
42.3333	0.0742	0.6
50.8	0.0618	0.5
63.5	0.0495	0.4
84.6667	0.0371	0.3

Diametral Pitch	Circular Pitch	Module	Diametral Pitch	Circular Pitch	Module	Diametral Pitch
0.3387	9.2764	75	2.3091	1.3605	11	9.4342
0.3629	8.658	70	2.3936	1.3125	8.467	10
0.3908	8.0395	65	2.5	1.2566	10.16	10.0531
0.4233	7.4211	60	2.54	1.2369	10	10.16
0.4618	6.8027	55	2.75	1.1424	9.236	10.9846
0.5	6.2832	50.8	2.7925	1.125	8.085	11
0.508	6.1843	50	2.8222	1.1132	9	11.2889
0.5644	5.5658	45	2.9568	1.0625	8	12
0.6048	5.1948	42	3	1.0472	8.467	12.5664
0.6513	4.8237	39	3.1416	1	7.58	12.7
0.7056	4.4527	36	3.175	0.9895	8	13
0.75	4.1888	33.867	3.351	0.9375	7.257	14
0.7697	4.0816	33	3.5	0.8976	7.257	14.1514
0.7854	4	12.128	3.5904	0.875	7.074	14.5143
0.8467	3.7106	30	3.6286	0.8658	7	15
0.8976	3.5	12	3.8666	0.8125	7	15.708
0.9407	3.3395	27	3.9077	0.804	6.5	16
1	3.1416	25.4	4	0.7854	6.35	16.7552
1.0472	3	11.622	4.1888	0.75	6.569	16.9333
1.0583	2.9684	24	4.2333	0.7421	6	17
1.1424	2.75	11.289	4.5	0.6981	5.644	18
1.1545	2.7211	22	4.5696	0.6875	6.5	18.812
1.25	2.5133	20.32	4.6182	0.6803	5.5	19
1.2566	2.5	11.117	4.71	0.667	6.35	20
1.27	2.4737	20	5	0.6283	5.08	20.32
1.3963	2.25	11	5.0266	0.625	6.064	22
1.4111	2.2263	18	5.08	0.6184	5	24
1.5	2.0944	16.933	5.5851	0.5625	6	25.4
1.5708	2	10.612	5.6444	0.5566	4.5	26
1.5875	1.979	16	6	0.5236	4.233	28
1.6755	1.875	10.16	6.2832	0.5	5.644	28.2222
1.6933	1.8553	15	6.35	0.4947	4	30
1.75	1.7952	14.514	6.7733	0.4638	3.75	31.75
1.7952	1.75	10	7	0.4488	3.629	32
1.8143	1.7316	14	7.1808	0.4375	5.558	34
1.9333	1.625	9.236	7.2571	0.4329	3.5	36
1.9538	1.6079	13	7.8154	0.402	3.25	36.2857
2	1.5708	12.7	7.854	0.4	5.5	42.3333
2.0944	1.5	9.096	8	0.3927	3.175	50.8
2.1167	1.4842	12	8.3776	0.375	5.393	63.5
2.1855	1.4375	9	8.4667	0.3711	3	84.6667
2.25	1.3963	11.289	9	0.3491	2.822	-
2.2848	1.375	8.59	9.2364	0.3401	2.75	-

Diametral Pitch	Circular Pitch	Module
9.4342	0.333	5.08
10	0.3142	2.54
10.0531	0.3125	5.053
10.16	0.3092	2.5
10.9846	0.286	5
11	0.2856	2.309
11.2889	0.2783	2.25
12	0.2618	2.117
12.5664	0.25	4.548
12.7	0.2474	2
13	0.2417	1.954
14	0.2244	1.814
14.1514	0.222	4.5
14.5143	0.2164	1.75
15	0.2094	1.693
15.708	0.2	4.233
16	0.1964	1.588
16.7552	0.1875	4.043
16.9333	0.1855	1.5
17	0.1848	1.494
18	0.1745	1.411
18.812	0.167	4
19	0.1653	1.337
20	0.1571	1.27
20.32	0.1546	1.25
22	0.1428	1.155
24	0.1309	1.058
25.4	0.1237	1
26	0.1208	0.977
28	0.1122	0.907
28.2222	0.1113	0.9
30	0.1047	0.847
31.75	0.0989	0.8
32	0.0982	0.794
34	0.0924	0.747
36	0.0873	0.706
36.2857	0.0866	0.7
42.3333	0.0742	0.6
50.8	0.0618	0.5
63.5	0.0495	0.4
84.6667	0.0371	0.3
-	-	-
-	-	-

Gear Diametral Pitch, Module Conversion Table Chart

Spur Gear Conversion (Units in inches)

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