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42 mph is equal to approximately 67.5928 kmh.
To convert 42 miles per hour (mph) to kilometers per hour (kmh), multiply the speed value by 1.60934, since 1 mile equals 1.60934 kilometers. This gives the equivalent speed in kmh.
Conversion Tool
Result in kmh:
Conversion Formula
The formula to convert miles per hour to kilometers per hour is:
kmh = mph × 1.60934
This formula works because one mile is equal to about 1.60934 kilometers. So by multiplying the miles per hour by this value, you get the speed in kilometers per hour. The conversion factor accounts for the difference in units between the imperial system (miles) and metric system (kilometers).
For example, converting 42 mph:
- Start with 42 mph.
- Multiply by 1.60934: 42 × 1.60934 = 67.59228.
- The result is approximately 67.59 kmh.
Conversion Example
- Convert 30 mph to kmh:
- Multiply 30 by 1.60934.
- 30 × 1.60934 = 48.2802 kmh.
- So, 30 mph equals roughly 48.28 kmh.
- Convert 55 mph to kmh:
- 55 × 1.60934 = 88.5137 kmh.
- This means 55 mph is about 88.51 kmh.
- Convert 10 mph to kmh:
- 10 × 1.60934 = 16.0934 kmh.
- So 10 mph equals 16.09 kmh approximately.
- Convert 65 mph to kmh:
- 65 × 1.60934 = 104.6071 kmh.
- That means 65 mph is about 104.61 kmh.
Conversion Chart
This chart shows mph values from 17.0 to 67.0, and their corresponding kmh conversions. You can quickly find the equivalent speed in kmh without calculating:
| mph | kmh |
|---|---|
| 17.0 | 27.3588 |
| 22.0 | 35.4055 |
| 27.0 | 43.4522 |
| 32.0 | 51.4989 |
| 37.0 | 59.5456 |
| 42.0 | 67.5923 |
| 47.0 | 75.6390 |
| 52.0 | 83.6857 |
| 57.0 | 91.7324 |
| 62.0 | 99.7791 |
| 67.0 | 107.8258 |
To use the chart, find the mph value in the left column, then look across to see the converted kmh value. Useful when a quick conversion is needed without a calculator.
Related Conversion Questions
- How fast is 42 mph in kilometers per hour exactly?
- What does 42 mph convert to in kmh for running speed?
- Is 42 miles per hour faster than 67 kmh?
- How to convert 42 mph to kmh without a calculator?
- What is 42 mph in kilometers per hour rounded to two decimals?
- Does 42 mph equal more or less than 70 kmh?
- What is the formula to convert 42 mph into kmh?
Conversion Definitions
mph: Miles per hour (mph) is a unit measuring speed in the imperial system. It represents the number of miles traveled in one hour. Commonly used in the United States and United Kingdom for road speed limits and vehicle speeds, mph quantifies how fast an object moves relative to time.
kmh: Kilometers per hour (kmh) is a metric unit of speed describing how many kilometers are covered in one hour. It is widely used worldwide for traffic speeds and scientific measurements. Kilometers per hour gives a consistent measurement across countries using the metric system.
Conversion FAQs
Why do we multiply by 1.60934 to convert mph to kmh?
Multiplying by 1.60934 changes the unit from miles to kilometers because one mile equals approximately 1.60934 kilometers. Since speed is distance over time, converting the distance unit requires this factor. The time unit (hours) remains the same so only distance is adjusted.
Can I convert kmh back to mph using the same method?
No, to convert kmh back to mph you divide by 1.60934 instead of multiplying. Because kilometers are larger than miles, dividing by the factor shrinks the value back into miles per hour.
Is the factor 1.60934 exact or approximate?
The factor 1.60934 is an approximation but very close to the exact conversion. It’s accurate enough for most everyday uses like driving speeds or casual calculations. For ultra-precise applications, more decimal places might be needed.
Why do some speedometers show both mph and kmh?
Vehicles often show both units because different countries use different systems. Having dual readouts helps drivers understand their speed depending on local regulations without needing conversion tools.
What if I want to convert fractional mph values?
The same formula applies regardless of whether the mph value is an integer or fractional. For example, 42.5 mph × 1.60934 equals about 68.390 kmh, calculated by multiplying the exact decimal value.
