Drill series · Metric

Metric Drill Sizes — Decimal Inch and Millimetre Chart

Name: Metric Drill Sizes — decimal inch and millimetre equivalents
Creator: ShopMath

https://shopmath.org/drills/metric · data verified August 1, 2026

The metric drill sizes run from 0.2 mm at 0.0079 in (0.200 mm) to 25 mm at 0.9843 in (25.000 mm), and 45 of the 227 sizes are the default tap drill for at least one standard thread. Metric twist drills, 0.2 mm to 25 mm on the BS 328 increment pattern.

Sizes: 227
Smallest: 0.2 mm
Largest: 25 mm
Standard: ANSI/ASME B94.11M

Every Metric Drill Bit Size, in Inches and Millimetres

227 sizes, ordered smallest to largest. Every row links to that drill's own page, with its equivalents in the other three indexes and the threads it taps.

Metric Drill Sizes — decimal inch and millimetre equivalents
Property	Diameter		Property
Drill	in	mm	Tap drill for
0.2 mm	0.0079	0.200	—
0.22 mm	0.0087	0.220	—
0.25 mm	0.0098	0.250	—
0.28 mm	0.0110	0.280	—
0.3 mm	0.0118	0.300	—
0.32 mm	0.0126	0.320	—
0.35 mm	0.0138	0.350	—
0.38 mm	0.0150	0.380	—
0.4 mm	0.0157	0.400	—
0.42 mm	0.0165	0.420	—
0.45 mm	0.0177	0.450	—
0.48 mm	0.0189	0.480	—
0.5 mm	0.0197	0.500	—
0.52 mm	0.0205	0.520	—
0.55 mm	0.0217	0.550	—
0.58 mm	0.0228	0.580	—
0.6 mm	0.0236	0.600	—
0.62 mm	0.0244	0.620	—
0.65 mm	0.0256	0.650	—
0.68 mm	0.0268	0.680	—
0.7 mm	0.0276	0.700	—
0.72 mm	0.0283	0.720	—
0.75 mm	0.0295	0.750	—
0.78 mm	0.0307	0.780	—
0.8 mm	0.0315	0.800	—
0.82 mm	0.0323	0.820	—
0.85 mm	0.0335	0.850	—
0.88 mm	0.0346	0.880	—
0.9 mm	0.0354	0.900	—
0.92 mm	0.0362	0.920	—
0.95 mm	0.0374	0.950	—
0.98 mm	0.0386	0.980	—
1 mm	0.0394	1.000	—
1.05 mm	0.0413	1.050	—
1.1 mm	0.0433	1.100	—
1.15 mm	0.0453	1.150	—
1.2 mm	0.0472	1.200	—
1.25 mm	0.0492	1.250	M1.6×0.35
1.3 mm	0.0512	1.300	—
1.35 mm	0.0532	1.350	—
1.4 mm	0.0551	1.400	M1.6×0.2
1.45 mm	0.0571	1.450	M1.8×0.35
1.5 mm	0.0591	1.500	—
1.55 mm	0.0610	1.550	—
1.6 mm	0.0630	1.600	M1.8×0.2 M2×0.4
1.65 mm	0.0650	1.650	—
1.7 mm	0.0669	1.700	—
1.75 mm	0.0689	1.750	M2×0.25
1.8 mm	0.0709	1.800	—
1.85 mm	0.0728	1.850	—
1.9 mm	0.0748	1.900	—
1.95 mm	0.0768	1.950	—
2 mm	0.0787	2.000	—
2.05 mm	0.0807	2.050	M2.5×0.45
2.1 mm	0.0827	2.100	—
2.15 mm	0.0846	2.150	M2.5×0.35
2.2 mm	0.0866	2.200	—
2.25 mm	0.0886	2.250	—
2.3 mm	0.0906	2.300	—
2.35 mm	0.0925	2.350	—
2.4 mm	0.0945	2.400	—
2.45 mm	0.0965	2.450	—
2.5 mm	0.0984	2.500	M3×0.5
2.55 mm	0.1004	2.550	—
2.6 mm	0.1024	2.600	—
2.65 mm	0.1043	2.650	M3×0.35
2.7 mm	0.1063	2.700	—
2.75 mm	0.1083	2.750	—
2.8 mm	0.1102	2.800	—
2.85 mm	0.1122	2.850	—
2.9 mm	0.1142	2.900	M3.5×0.6
2.95 mm	0.1161	2.950	—
3 mm	0.1181	3.000	—
3.1 mm	0.1220	3.100	—
3.2 mm	0.1260	3.200	M3.5×0.35
3.3 mm	0.1299	3.300	M4×0.7
3.4 mm	0.1339	3.400	—
3.5 mm	0.1378	3.500	M4×0.5
3.6 mm	0.1417	3.600	—
3.7 mm	0.1457	3.700	—
3.8 mm	0.1496	3.800	—
3.9 mm	0.1535	3.900	—
4 mm	0.1575	4.000	—
4.1 mm	0.1614	4.100	—
4.2 mm	0.1654	4.200	M5×0.8
4.3 mm	0.1693	4.300	—
4.4 mm	0.1732	4.400	—
4.5 mm	0.1772	4.500	M5×0.5
4.6 mm	0.1811	4.600	—
4.7 mm	0.1850	4.700	—
4.8 mm	0.1890	4.800	—
4.9 mm	0.1929	4.900	—
5 mm	0.1968	5.000	M6×1
5.1 mm	0.2008	5.100	—
5.2 mm	0.2047	5.200	—
5.3 mm	0.2087	5.300	M6×0.75
5.4 mm	0.2126	5.400	—
5.5 mm	0.2165	5.500	—
5.6 mm	0.2205	5.600	—
5.7 mm	0.2244	5.700	—
5.8 mm	0.2283	5.800	—
5.9 mm	0.2323	5.900	—
6 mm	0.2362	6.000	M7×1
6.1 mm	0.2402	6.100	—
6.2 mm	0.2441	6.200	—
6.3 mm	0.2480	6.300	M7×0.75
6.4 mm	0.2520	6.400	—
6.5 mm	0.2559	6.500	—
6.6 mm	0.2598	6.600	—
6.7 mm	0.2638	6.700	—
6.8 mm	0.2677	6.800	M8×1.25
6.9 mm	0.2717	6.900	—
7 mm	0.2756	7.000	M8×1
7.1 mm	0.2795	7.100	—
7.2 mm	0.2835	7.200	—
7.3 mm	0.2874	7.300	M8×0.75
7.4 mm	0.2913	7.400	—
7.5 mm	0.2953	7.500	—
7.6 mm	0.2992	7.600	—
7.7 mm	0.3031	7.700	—
7.8 mm	0.3071	7.800	—
7.9 mm	0.3110	7.900	—
8 mm	0.3150	8.000	—
8.1 mm	0.3189	8.100	—
8.2 mm	0.3228	8.200	—
8.3 mm	0.3268	8.300	—
8.4 mm	0.3307	8.400	—
8.5 mm	0.3346	8.500	M10×1.5
8.6 mm	0.3386	8.600	—
8.7 mm	0.3425	8.700	—
8.8 mm	0.3465	8.800	M10×1.25
8.9 mm	0.3504	8.900	—
9 mm	0.3543	9.000	M10×1
9.1 mm	0.3583	9.100	—
9.2 mm	0.3622	9.200	—
9.3 mm	0.3661	9.300	—
9.4 mm	0.3701	9.400	—
9.5 mm	0.3740	9.500	—
9.6 mm	0.3780	9.600	—
9.7 mm	0.3819	9.700	—
9.8 mm	0.3858	9.800	—
9.9 mm	0.3898	9.900	—
10 mm	0.3937	10.000	—
10.1 mm	0.3976	10.100	—
10.2 mm	0.4016	10.200	—
10.3 mm	0.4055	10.300	M12×1.75
10.4 mm	0.4094	10.400	—
10.5 mm	0.4134	10.500	M12×1.5
10.6 mm	0.4173	10.600	—
10.7 mm	0.4213	10.700	—
10.8 mm	0.4252	10.800	M12×1.25
10.9 mm	0.4291	10.900	—
11 mm	0.4331	11.000	—
11.1 mm	0.4370	11.100	—
11.2 mm	0.4409	11.200	—
11.3 mm	0.4449	11.300	—
11.4 mm	0.4488	11.400	—
11.5 mm	0.4528	11.500	—
11.6 mm	0.4567	11.600	—
11.7 mm	0.4606	11.700	—
11.8 mm	0.4646	11.800	—
11.9 mm	0.4685	11.900	—
12 mm	0.4724	12.000	—
12.1 mm	0.4764	12.100	M14×2
12.2 mm	0.4803	12.200	—
12.3 mm	0.4843	12.300	—
12.4 mm	0.4882	12.400	—
12.5 mm	0.4921	12.500	M14×1.5
12.6 mm	0.4961	12.600	—
12.7 mm	0.5000	12.700	—
12.8 mm	0.5039	12.800	—
12.9 mm	0.5079	12.900	—
13 mm	0.5118	13.000	—
13.1 mm	0.5157	13.100	—
13.2 mm	0.5197	13.200	—
13.3 mm	0.5236	13.300	—
13.4 mm	0.5276	13.400	—
13.5 mm	0.5315	13.500	—
13.6 mm	0.5354	13.600	—
13.7 mm	0.5394	13.700	—
13.8 mm	0.5433	13.800	—
13.9 mm	0.5472	13.900	—
14 mm	0.5512	14.000	M16×2
14.25 mm	0.5610	14.250	—
14.5 mm	0.5709	14.500	M16×1.5
14.75 mm	0.5807	14.750	—
15 mm	0.5906	15.000	—
15.25 mm	0.6004	15.250	—
15.5 mm	0.6102	15.500	M18×2.5
15.75 mm	0.6201	15.750	—
16 mm	0.6299	16.000	M18×2
16.25 mm	0.6398	16.250	—
16.5 mm	0.6496	16.500	M18×1.5
16.75 mm	0.6594	16.750	—
17 mm	0.6693	17.000	—
17.25 mm	0.6791	17.250	—
17.5 mm	0.6890	17.500	M20×2.5
17.75 mm	0.6988	17.750	—
18 mm	0.7087	18.000	M20×2
18.25 mm	0.7185	18.250	—
18.5 mm	0.7283	18.500	M20×1.5
18.75 mm	0.7382	18.750	—
19 mm	0.7480	19.000	—
19.25 mm	0.7579	19.250	—
19.5 mm	0.7677	19.500	M22×2.5
19.75 mm	0.7776	19.750	—
20 mm	0.7874	20.000	M22×2
20.25 mm	0.7972	20.250	—
20.5 mm	0.8071	20.500	M22×1.5
20.75 mm	0.8169	20.750	—
21 mm	0.8268	21.000	M24×3
21.25 mm	0.8366	21.250	—
21.5 mm	0.8465	21.500	—
21.75 mm	0.8563	21.750	—
22 mm	0.8661	22.000	M24×2
22.25 mm	0.8760	22.250	—
22.5 mm	0.8858	22.500	—
22.75 mm	0.8957	22.750	—
23 mm	0.9055	23.000	—
23.25 mm	0.9154	23.250	—
23.5 mm	0.9252	23.500	—
23.75 mm	0.9350	23.750	—
24 mm	0.9449	24.000	M27×3
24.25 mm	0.9547	24.250	—
24.5 mm	0.9646	24.500	—
24.75 mm	0.9744	24.750	—
25 mm	0.9843	25.000	M27×2 M30×2 M30×3.5+20

Diameters are nominal. The tap-drill column shows the threads whose shop-default tap drill is that size; a drill with no entry there is still a standard size, it is simply not the default drill for any thread in this reference.

Sources and Method for the Metric Drill Bit Chart

Metric drill diameterscomputed

Number/letter: bd_warehouse drill_sizes.csv (Apache-2.0) cross-checked against Wikipedia Drill bit sizes (CC BY-SA 4.0). Fractional: computed 1/64 in steps per ANSI B94.11M. Metric: computed BS 328 increment pattern.

Verified against Wikipedia Drill bit sizes (CC BY-SA 4.0); 31/31 checks passed

Computed from the standard's formulas, then checked against published tables.

Assumptions

Diameters are nominal. Manufacturing tolerance, wear and run-out all cut oversize.
Dataset scope: Number sizes #61-#80 are stored but tagged demandTier 'extended' — query-space-map.md Appendix A found the tail thinning in the 60s. Sizes below #80 and metric sizes above 25.0 mm excluded.

Data last verified

August 1, 2026

How this data is built and checked →

How to Cite This Metric Drill Bit Chart

Citation

ShopMath. "Metric Drill Sizes — Decimal Inch and Millimetre Chart." ShopMath, verified August 1, 2026, https://shopmath.org/drills/metric

BibTeX

@misc{shopmath-drills-metric,
  title        = {Metric Drill Sizes — Decimal Inch and Millimetre Chart},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/drills/metric}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/drills/metric

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