Welcome to the definitive guide to converting inches to millimeters! Whether you're an engineer, a DIY enthusiast, or simply need to transform standard measurements into metrics, this page is the ideal tool. Here you will find an easy and accurate way to convert the inch dimensions of bearings, oil seals and various mechanical components to millimeters. Our goal is to provide you with a reliable, easy-to-use resource for all your conversion needs.
History of inches and millimeters
The history of inches and millimeters is fascinating and goes back many centuries, reflecting the development of units of measurement throughout human history.
The thumb: an ancient measurement
- Origins : The inch, as a unit of measurement, has ancient origins. Its name comes from the Latin “uncia”, which means “twelfth part”, reflecting its initial use as a twelfth of the Roman foot.
- Standardization : Over the centuries, the exact length of the thumb varied greatly, often based on the length of the ruler's thumb. Only in 1959 was the thumb finally standardized internationally, setting it at exactly 25.4 millimeters.
The Millimeter: Metric Precision
- Development of the Metric System : The millimeter is a unit of length in the metric system, introduced in France after the French Revolution. The metric system was designed to have units of measurement based on natural and universal principles, as opposed to traditional measurements that varied greatly from place to place.
- Global Diffusion : With the adoption of the metric system by several countries throughout the 19th and 20th centuries, the millimeter became an international standard for the precise measurement of small lengths, used in science, engineering and many other applications.
From tradition to uniformity
The transition from the inch to the millimeter is emblematic of the transition from measurement systems based on traditional, local standards to a uniform international system. Although the inch continues to be used, especially in Anglo-Saxon countries, for everyday applications and in some industrial sectors, the millimeter is widely used in most parts of the world for applications that require precision and standardization.
This evolution reflects not only technological and scientific advances, but also a desire for unity and consistency in measurements at a global level.
FAQs about converting millimeters to inches
1. How to convert millimeters to inches?
The conversion from millimeters to inches is done by dividing the number of millimeters by 25.4, as one inch is exactly 25.4 millimeters. For example, to convert 10 mm to inches, you divide 10 by 25.4, resulting in approximately 0.3937 inches.
2. How many inches are 10 millimeters?
10 millimeters equals approximately 0.3937 inches. This is calculated by dividing 10 by 25.4.
3. What is the formula for converting millimeters to inches?
The formula to convert millimeters to inches is: Inches = Millimeters / 25.4.
4. Is there a quick way to approximate millimeters to inches without using a calculator?
A quick way to approximate is to divide the number of millimeters by 25 to get an estimate in inches. This method provides a reasonably accurate approximation without the need to perform complex calculations.
5. How can I convert precise measurements such as 15.24 mm to inches?
To convert precise measurements, divide the number of millimeters (in this case 15.24) by 25.4. Therefore, 15.24 mm is exactly 0.6 inches.
6. Is there a significant difference between approximate and precise conversion?
For most practical applications, the approximation is sufficiently accurate. However, in contexts where high precision is required, such as engineering or precision machining, it is advisable to use the precise formula.
Quick inches to mm conversions:
How many MMs is an inch?
1 inch = 25.4 millimeters.
How many inches are 5 mm?
5 mm = just over 3/16 of an inch. 6 mm = almost 1/4 inch. 7 mm = almost 9/32 of an inch (= just over 1/4 of an inch) 8 mm = 5/16 of an inch.
How many mm equal 3/4 of an inch?
3/4 of an inch equals 19.05 mm.
How many millimeters is one and a half inches?
One and a half inches equals 12.7 mm.
Inch/millimeter conversion table:
| Inches | mm |
| 1/32 | 0.79 |
| 3/64 | 1.19 |
| 01/16 | 1.59 |
| 5/64 | 1.98 |
| 03/32 | 2.38 |
| 7/64 | 2.78 |
| 1/8 | 3.18 |
| 9/64 | 3.57 |
| 05/32 | 3.97 |
| 11/64 | 4.37 |
| 03/16 | 4.76 |
| 13/64 | 5.16 |
| 07/32 | 5.56 |
| 15/64 | 5.95 |
| 1/4 | 6:35 am |
| 17/64 | 6.75 |
| 09/32 | 7.14 |
| 19/64 | 7.54 |
| 05/16 | 7.94 |
| 21/64 | 8.33 |
| 11/32 | 8.73 |
| 23/64 | 9.13 |
| 3/8 | 9.53 |
| 25/64 | 9.92 |
| 13/32 | 10:32 am |
| 27/64 | 10.72 |
| 7/16 | 11.11 |
| 29/64 | 11.51 |
| 15/32 | 11.91 |
| 31/64 | 12:30 p.m. |
| 1/2 | 12:70 p.m. |
| 33/64 | 1:10 p.m. |
| 17/32 | 1:49 p.m. |
| 35/64 | 13.89 |
| 16/09 | 2:29 p.m. |
| 37/64 | 14.68 |
| 19/32 | 15.08 |
| 39/64 | 3:48 p.m. |
| 5/8 | 15.88 |
| 41/64 | 16.27 |
| 21/32 | 16.67 |
| 43/64 | 17.07 |
| 11/16 | 5:46 p.m. |
| 45/64 | 17.86 |
| 23/32 | 6:26 p.m. |
| 47/64 | 6:65 p.m. |
| 3/4 | 19.05 |
| 49/64 | 7:45 p.m. |
| 25/32 | 19.84 |
| 51/64 | 8:24 p.m. |
| 13/16 | 8:64 p.m. |
| 53/64 | 21.03 |
| 27/32 | 9:43 p.m. |
| 55/64 | 21.83 |
| 7/8 | 10:23 p.m. |
| 57/64 | 10:62 p.m. |
| 29/32 | 23.02 |
| 59/64 | 23.42 |
| 15/16 | 23.81 |
| 61/64 | 24.21 |
| 31/32 | 24.61 |
| 63/64 | 25:00 |
| Inches | mm |
| 1 | 25:40 |
| 11/32 | 26.19 |
| 11/16 | 26.99 |
| 13/32 | 27.78 |
| 1 1/8 | 28.58 |
| 15/32 | 29.37 |
| 1 3/16 | 30.16 |
| 17/32 | 30.96 |
| 1 1/4 | 31.75 |
| 19/32 | 32.54 |
| 05/16 | 33.34 |
| 11/32 | 34.13 |
| 1 3/8 | 34.93 |
| 113/32 | 35.72 |
| 7/16 | 36.51 |
| 115/32 | 37.31 |
| 1 1/2 | 38.1 |
| 117/32 | 38.89 |
| 16/09 | 39.69 |
| 119/32 | 40.48 |
| 1 5/8 | 41.28 |
| 121/32 | 42.07 |
| 11/16 | 42.86 |
| 123/32 | 43.66 |
| 1 3/4 | 44.45 |
| 125/32 | 45.24 |
| 113/16 | 46.04 |
| 127/32 | 46.83 |
| 17/8 | 47.63 |
| 129/32 | 48.42 |
| 115/16 | 49.21 |
| 131/32 | 50.01 |
| Inches | mm |
| two | 50.80 |
| 21/32 | 51.59 |
| 21/16 | 52.39 |
| 2 3/32 | 53.18 |
| 2 1/8 | 53.98 |
| 25/32 | 54.77 |
| 2 3/16 | 55.56 |
| 2 7/32 | 56.36 |
| 2 1/4 | 57.15 |
| 2 9/32 | 57.94 |
| 2 16/05 | 58.74 |
| 2 11/32 | 59.53 |
| 2 3/8 | 60.33 |
| 2 13/32 | 61.12 |
| 2 7/16 | 61.91 |
| 2 15/32 | 62.71 |
| 2 1/2 | 63.5 |
| 2 17/32 | 64.29 |
| 2 16/09 | 65.09 |
| 2 19/32 | 65.88 |
| 2 5/8 | 66.68 |
| 2 21/32 | 67.47 |
| 2 11/16 | 68.26 |
| 2 23/32 | 69.06 |
| 2 3/4 | 69.85 |
| 2 25/32 | 70.64 |
| 2 13/16 | 71.44 |
| 2 27/32 | 72.23 |
| 2 7/8 | 73.03 |
| 2 29/32 | 73.82 |
| 2 15/16 | 74.61 |
| 2 31/32 | 75.41 |
| Inches | mm |
| 3 | 76.20 |
| 3 1/32 | 76.99 |
| 3 1/16 | 77.79 |
| 3 3/32 | 78.58 |
| 3 1/8 | 79.38 |
| 3 5/32 | 80.17 |
| 3 16/03 | 80.96 |
| 3 7/32 | 81.76 |
| 3 1/4 | 82.55 |
| 3 9/32 | 83.34 |
| 3 16/05 | 84.14 |
| 3 11/32 | 84.93 |
| 3 3/8 | 85.73 |
| 3 13/32 | 86.52 |
| 3 16/07 | 87.31 |
| 3 15/32 | 88.11 |
| 3 1/2 | 88.9 |
| 3 17/32 | 89.69 |
| 3 16/09 | 90.49 |
| 3 19/32 | 91.28 |
| 3 5/8 | 92.08 |
| 3 21/32 | 92.87 |
| 3 11/16 | 93.66 |
| 3 23/32 | 94.46 |
| 3 3/4 | 95.25 |
| 3 25/32 | 96.04 |
| 3 13/16 | 96.84 |
| 3 27/32 | 97.63 |
| 3 7/8 | 98.43 |
| 3 29/32 | 99.22 |
| 3 15/16 | 100.01 |
| 3 31/32 | 100.81 |
| Inches | mm |
| 4 | 101.60 |
| 4 1/32 | 102.39 |
| 4 1/16 | 103.19 |
| 43/32 | 103.98 |
| 4 1/8 | 104.78 |
| 4 5/32 | 105.57 |
| 4 3/16 | 106.36 |
| 4 7/32 | 107.16 |
| 4 1/4 | 107.95 |
| 4 9/32 | 108.74 |
| 4 5/16 | 109.54 |
| 4 11/32 | 110.33 |
| 4 3/8 | 111.13 |
| 4 13/32 | 111.92 |
| 4 7/16 | 112.71 |
| 4 15/32 | 113.51 |
| 4 1/2 | 114.3 |
| 4 17/32 | 115.09 |
| 4 16/09 | 115.89 |
| 4 19/32 | 116.68 |
| 4 5/8 | 117.48 |
| 4 21/32 | 118.27 |
| 4 11/16 | 119.06 |
| 4 23/32 | 119.86 |
| 4 3/4 | 120.65 |
| 4 25/32 | 121.44 |
| 4 13/16 | 122.24 |
| 4 27/32 | 123.03 |
| 4 7/8 | 123.83 |
| 4 29/32 | 124.62 |
| 4 15/16 | 125.41 |
| 4 31/32 | 126.21 |
| Inches | mm |
| 5 | 127.00 |
| 5 1/32 | 127.79 |
| 5 1/16 | 128.59 |
| 5 3/32 | 129.38 |
| 5 1/8 | 130.18 |
| 5 5/32 | 130.97 |
| 5 03/16 | 131.76 |
| 5 7/32 | 132.56 |
| 5 1/4 | 133.35 |
| 5 09/32 | 134.14 |
| 5 5/16 | 134.94 |
| 5 11/32 | 135.73 |
| 5 3/8 | 136.53 |
| 5 13/32 | 137.32 |
| 5 16/07 | 138.11 |
| 5 15/32 | 138.91 |
| 5 1/2 | 139.7 |
| 5 17/32 | 140.49 |
| 5 16/09 | 141.29 |
| 5 19/32 | 142.08 |
| 5 5/8 | 142.88 |
| 5 21/32 | 143.67 |
| 5 11/16 | 144.46 |
| 5 23/32 | 145.26 |
| 5 3/4 | 146.05 |
| 5 25/32 | 146.84 |
| 5 13/16 | 147.64 |
| 5 27/32 | 148.43 |
| 5 7/8 | 149.23 |
| 5 29/32 | 150.02 |
| 5 15/16 | 150.81 |
| 5 31/32 | 151.61 |
| Inches | mm |
| 6 | 152.40 |
| 6 1/32 | 153.19 |
| 6 1/16 | 153.99 |
| 6 3/32 | 154.78 |
| 6 1/8 | 155.58 |
| 6 32/05 | 156.37 |
| 6 03/16 | 157.16 |
| 6 7/32 | 157.96 |
| 6 1/4 | 158.75 |
| 6 9/32 | 159.54 |
| 6 16/05 | 160.34 |
| 6 11/32 | 161.13 |
| 6 3/8 | 161.93 |
| 6 13/32 | 162.72 |
| 6 7/16 | 163.51 |
| 6 15/32 | 164.31 |
| 6 1/2 | 165.1 |
| 6 17/32 | 165.89 |
| 6 16/09 | 166.69 |
| 6 19/32 | 167.48 |
| 6 5/8 | 168.28 |
| 6 21/32 | 169.07 |
| 6 11/16 | 169.86 |
| 6 23/32 | 170.66 |
| 6 3/4 | 171.45 |
| 6 25/32 | 172.24 |
| 6 13/16 | 173.04 |
| 6 27/32 | 173.83 |
| 6 7/8 | 174.63 |
| 6 29/32 | 175.42 |
| 6 15/16 | 176.21 |
| 6 31/32 | 177.01 |
| Inches | mm |
| 7 | 177.80 |
| 7 1/32 | 178.59 |
| 7 1/16 | 179.39 |
| 7 3/32 | 180.18 |
| 7 1/8 | 180.98 |
| 7 32/05 | 181.77 |
| 7 03/16 | 182.56 |
| 7 7/32 | 183.36 |
| 7 1/4 | 184.15 |
| 7 09/32 | 184.94 |
| 7 16/05 | 185.74 |
| 7 11/32 | 186.53 |
| 7 3/8 | 187.33 |
| 7 13/32 | 188.12 |
| 7 7/16 | 188.91 |
| 7 15/32 | 189.71 |
| 7 1/2 | 190.5 |
| 7 17/32 | 191.29 |
| 7 16/09 | 192.09 |
| 7 19/32 | 192.88 |
| 7 5/8 | 193.68 |
| 7 21/32 | 194.47 |
| 7 11/16 | 195.26 |
| 7 23/32 | 196.06 |
| 7 3/4 | 196.85 |
| 7 25/32 | 197.64 |
| 7 13/16 | 198.44 |
| 7 27/32 | 199.23 |
| 7 7/8 | 200.03 |
| 7 29/32 | 200.82 |
| 7 15/16 | 201.61 |
| 7 31/32 | 202.41 |
