1.5 inches is equal to 38.1 millimeters.
To convert 1.5 inches to millimeters, multiply the length value by 25.4 because there are 25.4 millimeters in one inch. This gives the equivalent length in millimeters.
Conversion Tool
Result in mm:
Conversion Formula
The formula to convert inches (in) to millimeters (mm) is:
mm = in × 25.4
This works because 1 inch equals exactly 25.4 millimeters. When you multiply the number of inches by 25.4, you get the length in millimeters. The factor 25.4 comes from international agreement and standard measurements.
Example calculation for 1.5 inches:
- Start with 1.5 inches
- Multiply by 25.4: 1.5 × 25.4 = 38.1
- Result: 38.1 millimeters
Conversion Example
- Example 1: Convert 2.3 in to mm
- Multiply 2.3 by 25.4
- 2.3 × 25.4 = 58.42 mm
- So, 2.3 inches equals 58.42 millimeters
- Example 2: Convert 0.75 in to mm
- Multiply 0.75 by 25.4
- 0.75 × 25.4 = 19.05 mm
- Therefore, 0.75 inches equals 19.05 millimeters
- Example 3: Convert 10 in to mm
- Multiply 10 by 25.4
- 10 × 25.4 = 254 mm
- Thus, 10 inches equals 254 millimeters
- Example 4: Convert 5.6 in to mm
- Multiply 5.6 by 25.4
- 5.6 × 25.4 = 142.24 mm
- So, 5.6 inches equals 142.24 millimeters
Conversion Chart
The chart below lists values from -23.5 inches up to 26.5 inches, each converted into millimeters. To use the chart, find the value in inches on the left column, then look right to see its equivalent in millimeters. Negative values represent lengths in the opposite direction or below a reference point.
| Inches (in) | Millimeters (mm) |
|---|---|
| -23.5 | -596.9 |
| -20.0 | -508.0 |
| -15.5 | -393.7 |
| -10.0 | -254.0 |
| -5.0 | -127.0 |
| -1.0 | -25.4 |
| 0.0 | 0.0 |
| 1.0 | 25.4 |
| 5.5 | 139.7 |
| 10.0 | 254.0 |
| 15.0 | 381.0 |
| 20.0 | 508.0 |
| 23.5 | 596.9 |
| 26.5 | 673.1 |
Related Conversion Questions
- How many millimeters are in 1.5 inches exactly?
- What is the formula to convert 1.5 in to mm?
- Can I convert 1.5 inches to millimeters manually?
- How accurate is the conversion of 1.5 in to mm?
- Is 1.5 inches more or less than 38 mm?
- What is 1.5 inches in millimeters rounded to two decimals?
- Why multiply by 25.4 when converting 1.5 inches to mm?
Conversion Definitions
In (Inch): An inch is a unit of length in the imperial and US customary systems, equal to exactly 2.54 centimeters or 25.4 millimeters. It is commonly used in the United States, Canada, and the United Kingdom for measuring small distances, heights, and screen sizes, among others.
mm (Millimeter): A millimeter is a metric unit of length equal to one thousandth of a meter. It is used worldwide for precise measurements in engineering, manufacturing, and science. One millimeter equals 0.03937 inches and often measures small objects or dimensions.
Conversion FAQs
Why is 1 inch equal to 25.4 millimeters?
The inch was defined internationally in 1959 as exactly 25.4 millimeters to standardize measurements across countries. Before, slight variations existed between countries. This fixed value allows for consistent conversions and manufacturing tolerances worldwide.
Can I use this conversion for very small measurements?
Yes, converting inches to millimeters works for any value, big or small. Millimeters offer finer resolution than inches, so converting small inch values to millimeters gives more precise numbers useful in detailed work like machining or tailoring.
What if my inch measurement has decimals like 1.5?
Decimal inches such as 1.5 inches can be converted exactly by multiplying by 25.4. The decimal allows for fractional inch values, and the result in millimeters will be a decimal number too, representing the equivalent precise length.
Does negative inch value conversion have any special meaning?
Negative inch values indicate a length in the opposite direction or below a reference point, such as depth or displacement. The conversion formula stays unchanged; multiply by 25.4 and the result will be negative millimeters as well.
Are conversions between inches and millimeters reversible without error?
Converting inches to millimeters and back can introduce small rounding errors due to decimal precision. Using adequate decimal places reduces error. Always keep enough decimals in intermediate steps if accuracy is critical.