Inch » Metric Conversion Chart

Most of the router bits in our catalogue are manufactured to imperial specifications as this is the current standard for South Africa for the past 40 years. Since most woodworkers work with metric measurements, we made the conversion chart available for you to use at your convenience.

Kindly keep in mind that you should consider the maximum speed rating for the router bit you plan to use.

We took the liberty to mark all the sizes mostly used in bold with a green background.

 

Here are the general sizes for our bits:

 

INCHES METRIC
FRACTIONAL DECIMAL mm
3/32 0.0938 2.3813
- - 0.0945 2.4000
- - 0.0984 2.5000
7/64 0.1094 2.7781
- - 0.1181 3.0000
1/8 0.1250 3.1750
- - 0.1378 3.5000
9/64 0.1406 3.5719
5/32 0.1563 3.9688
- - 0.1575 4.0000
11/64 0.1719 4.3656
- - 0.1772 4.5000
3/16 0.1875 4.7625
- - 0.1969 5.0000
13/64 0.2031 5.1594
- - 0.2165 5.5000
7/32 0.2188 5.5563
15/64 0.2344 5.9531
- - 0.2362 6.0000
1/4 0.2500 6.3500
- - 0.2559 6.5000
17/64 0.2656 6.7469
- - 0.2756 7.0000
9/32 0.2813 7.1438
- - 0.2953 7.5000
19/64 0.2969 7.5406
5/16 0.3125 7.9375
- - 0.3150 8.0000
21/64 0.3281 8.3344
- - 0.3346 8.5000
11/32 0.3438 8.7313
- - 0.3543 9.0000
23/64 0.3594 9.1281
- - 0.3740 9.5000
3/8 0.3750 9.5250
25/64 0.3906 9.9219
- - 0.3937 10.0000
13/32 0.4063 10.3188
- - 0.4134 10.5000
27/64 0.4219 10.7156
- - 0.4331 11.0000
7/16 0.4375 11.1125
- - 0.4528 11.5000
29/64 0.4531 11.5094
15/32 0.4688 11.9063
- - 0.4724 12.0000
31/64 0.4844 12.3031
- - 0.4921 12.5000
1/2 0.5000 12.7000
- - 0.5118 13.0000
33/64 0.5156 13.0969
17/32 0.5313 13.4938
- - 0.5315 13.5000
35/64 0.5469 13.8906
. 0.5512 14.0000
9/16 0.5625 14.2875
. 0.5709 14.5000
37/64 0.5781 14.6844
. 0.5906 15.0000
19/32 0.5938 15.0813
39/64 0.6094 15.4781
. 0.6102 15.5000
5/8 0.6250 15.8750
. 0.6299 16.0000
41/64 0.6406 16.2719
. 0.6496 16.5000
21/32 0.6563 16.6688
. 0.6693 17.0000
43/64 0.6719 17.0656
11/16 0.6875 17.4625
. 0.6890 17.5000
45/64 0.7031 17.8594
. 0.7087 18.0000
23/32 0.7188 18.2563
. 0.7283 18.5000
47/64 0.7344 18.6531
. 0.7480 19.0000

 

INCHES METRIC
FRACTIONAL DECIMAL mm
3/4 0.7500 19.0500
49/64 0.7656 19.4469
. 0.7677 19.5000
25/32 0.7813 19.8438
. 0.7874 20.0000
51/64 0.7969 20.2406
. 0.8071 20.5000
13/16 0.8125 20.6375
. 0.8268 21.0000
53/64 0.8281 21.0344
27/32 0.8438 21.4313
. 0.8465 21.5000
55/64 0.8594 21.8281
. 0.8661 22.0000
7/8 0.8750 22.2250
. 0.8858 22.5000
57/64 0.8906 22.6219
. 0.9055 23.0000
29/32 0.9063 23.0188
59/64 0.9219 23.4156
. 0.9252 23.5000
15/16 0.9375 23.8125
. 0.9449 24.0000
61/64 0.9531 24.2094
. 0.9646 24.5000
31/32 0.9688 24.6063
. 0.9843 25.0000
63/64 0.9844 25.0031
1 1.0000 25.4000
. 1.0039 25.5000
. 1.0236 26.0000
. 1.0433 26.5000
. 1.0630 27.0000
. 1.0827 27.5000
. 1.1024 28.0000
. 1.1220 28.5000
1 1/8   28.60
. 1.1417 29.0000
. 1.1614 29.5000
. 1.1811 30.0000
1 3/16   30.20
. 1.2205 31.0000
1 1/4 1.2500 31.7500
. 1.2598 32.0000
. 1.2992 33.0000
. 1.3386 34.0000
1 3/8   34.90
. 1.3780 35.0000
. 1.4173 36.0000
. 1.4567 37.0000
. 1.4961 38.0000
1 1/2 1.5000 38.1000
. 1.5354 39.0000
1 37/64  1.5748 40.0000
. 1.6142 41.0000
1 5/8   41.30
. 1.6535 42.0000
. 1.6929 43.0000
. 1.7323 44.0000
1 3/4 1.7500 44.4500
. 1.7717 45.0000
. 1.8110 46.0000
1 7/8 1.8504 47.60
. 1.8898 48.0000
. 1.9291 49.0000
. 1.9685 50.0000
2 2.0000 50.8000
. 2.0079 51.0000
. 2.0472 52.0000
. 2.0866 53.0000
2 1/8 2.1260 54.0000
2 1/4 2.2500 57.1500
2 1/2 2.5000 63.5000
2 3/4 2.7500 69.8500
3 3.0000 76.2000
3 1/2 3.5 88.9