Miles (mi) and Kilometers (km) Conversion Calculator

An online miles and kilometers conversion calculator is presented. Problems involving convertion of miles and kilometers are also included.
Abbreviations to miles and kilometers.
1 kilometer may be written as 1 km
1 mile may be written as 1 mi


Conversion Formula of Miles into Kilometers [1]

1 mile = 1.609344 kilometers.
1 kilometer = (1/1.609344) miles = 0.62137119223 miles


Examples of Conversion

Example 1 - Convert a 22.4 miles to km and round answer to the nearest km
22.4 miles = 22.4 1.609344 km = 36.0493056 km
Round to the nearest km is similar to rounding to the nearest unit.
22.4 miles = 36 km


Example 2 - Convert a 17,01 km into miles and round answer to the nearest tenth of a mile
17,01 km = (17.01 /1.609344) miles = 10.56952398 km
Round to the nearest tenth of a mile is similar to rounding to one decimal place.
17,01 km = 10.6 mi



Use of the Converter

Enter the number of miles (mi) or kilometers (Km) to be converted and convert.

mi         km

km         mi

Decimal Places

     

Problems Involving miles to kilometers Conversions

Problem 1
The fuel-efficiency of a car is 54.8 mpg (miles per gallon). What is the fuel-efficiency of this car in kilometer per gallon (km/g)? Round the results to 2 decimal places.

Solution
Convert 54.8 miles into km
54.8 mi = 54.8 1.609344 km = 88.1920512 km
The fuel-efficiency of the car rounded to two decimal places is
88.19 km/g



Problem 2
The speed limit in a highway is 110 km per hour (km/hr). What is the speed limit in miles per hour (mph) rounded to the nearest unit?

Solution
Convert 110 km into miles
110 km = ( 110/1.609344 ) mi = 68.3508311461 mi
The speed limit in miles per hour (mph) rounded to the nearest unit is
68 mph



Problem 3
How long does it take a car to cover a distance of 210 miles at the average speed of 90 km/hr? Write the answer as hours/minutes to the nearest minute.

Solution
Since the speed of the car is given in km/hr, we first need to convert the distance in km
210 mi = 210 1.609344 km = 337.96224 km
We now use the formula
Time = Distance / speed
Time = (337.96224 km) / (90 km/hr) = 3.755136 hr
Time = 3 hours + 0.755136*60 minutes = 3 hours + 45.30816 minutes
Round 45.30816 minutes to the nearest minute
Time = 3 hours / 45 minutes




More References and links

  1. www.nist.gove.pdf
  2. Online Calculators
  3. Units Conversion and Calculators
  4. Geometry Calculators