1.5 inches is equal to 38.1 millimeters.
The conversion from inches to millimeters involves multiplying the inch value by 25.4, since one inch equals 25.4 millimeters exactly. Therefore, 1.5 inches times 25.4 gives the equivalent length in millimeters.
Conversion Tool
Result in mm:
Conversion Formula
The formula to convert inches to millimeters is:
millimeters = inches × 25.4
This works because 1 inch is defined as exactly 25.4 millimeters. The conversion multiply the number of inches by this constant gives the equivalent length in millimeters.
Example calculation:
- Convert 1.5 inches to millimeters
- Multiply 1.5 by 25.4
- 1.5 × 25.4 = 38.1 millimeters
Conversion Example
- Convert 2 inches to millimeters:
- Multiply 2 × 25.4
- Result: 50.8 mm
- Convert 0.75 inches to millimeters:
- 0.75 × 25.4 = 19.05 mm
- Convert 5.2 inches to millimeters:
- 5.2 × 25.4 = 132.08 mm
- Convert -3 inches to millimeters:
- -3 × 25.4 = -76.2 mm
Conversion Chart
The table below shows a range of inch values from -23.5 to 26.5, and their corresponding millimeter conversions. You can use this chart to quickly find equivalent lengths without calculating manually.
| Inches | Millimeters (mm) |
|---|---|
| -23.5 | -23.5 × 25.4 = -596.9 |
| -20.0 | -508.0 |
| -15.5 | -393.7 |
| -10.0 | -254.0 |
| -5.0 | -127.0 |
| 0.0 | 0.0 |
| 5.0 | 127.0 |
| 10.0 | 254.0 |
| 15.0 | 381.0 |
| 20.0 | 508.0 |
| 23.5 | 23.5 × 25.4 = 596.9 |
| 26.5 | 26.5 × 25.4 = 673.1 |
Related Conversion Questions
- How many millimeters are in 1.5 inches exactly?
- What is the best way to convert 1.5 inch to mm manually?
- Can I use 1.5 inches to mm conversion for precise engineering work?
- Is 1.5 inch equal to 38.1 mm or a different value?
- Why does 1.5 inch convert to 38.1 millimeters and not another number?
- How do you convert fractions like 1.5 inch to millimeters?
- What formula should I apply to convert 1.5 inches into mm?
Conversion Definitions
Inch: An inch is a unit of length in the imperial and US customary systems, defined as exactly 25.4 millimeters. It is used mainly in the United States, Canada, and the UK for measuring small distances and objects, especially in construction, manufacturing, and daily life.
Millimeter (mm): A millimeter is a unit of length in the metric system, equal to one-thousandth of a meter. It is widely used worldwide for precise measurements in science, engineering, and everyday measurements, representing very small lengths or thicknesses.
Conversion FAQs
Why is 25.4 used as the multiplier when converting inches to millimeters?
The value 25.4 is the agreed international standard defining how many millimeters are in one inch. This exact conversion factor was established to maintain consistency in measurements globally, ensuring that lengths expressed in inches can be accurately converted to metric units without approximation.
Can I convert negative inches to millimeters?
Yes, negative values represent measurements in the opposite direction or below a reference point. The conversion formula applies the same way, multiplying the negative inch value by 25.4, resulting in a negative millimeter value.
Is the conversion factor for inches to mm ever changing?
No, the conversion factor 25.4 is fixed and internationally accepted since 1959. It will not change because it forms the basis for standardizing measurements between imperial and metric systems.
How accurate is converting inches to millimeters using this formula?
Using 25.4 as the multiplier produces exact conversions because one inch is defined as exactly 25.4 millimeters. Thus, the conversion is precise and accurate for any calculation or measurement.
Can decimal inches be converted the same way as whole inches?
Yes, decimal and fractional inch values are converted identically by multiplying them with 25.4. This makes the formula suitable for any real number value representing inches.