Unit Conversions

The first four sections below list commonly used equivalents between the SI (International System) units of weights and measures used in the metric system, and those used in the imperial system. A complete list of hexadecimal values with their binary equivalents is given in the corresponding section while an example of the conversion from GNSS Time of Week to calendar day is shown.

Distance

1 metre (m) = 100 centimetres (cm) = 1000 millimetres (mm)
1 kilometre (km) = 1000 metres (m)
1 nautical mile = 1852 m
1 international foot = 0.3048 m
1 statute mile = 1609.344 m
1 US survey foot = 0.3048006096 m
1 inch = 25.4 mm

Volume

1 litre (l) = 1000 cubic centimetres (cc)
1 gallon (Imperial) = 4.546 litres
1 gallon (US) = 3.785 litres

Temperature

degrees Celsius = (5/9) x [(degrees Fahrenheit) - 32]
degrees Fahrenheit = [(9/5) x (degrees Celsius)] + 32

Weight

1 kilogram (kg) = 1000 grams
1 pound = 0.4536 kilogram (kg)

Hexadecimal, Binary and Decimal Equivalents

Binary   Decimal      Binary   Decimal      Binary   Decimal      Binary   Decimal

10000        16             100101     37             111010     58             1001111   79

10001        17             100110     38             111011     59             1010000   80

10010        18             100111     39             111100     60             1010001   81

10011        19             101000     40             111101     61             1010010   82

10100        20             101001     41             111110     62             1010011   83

10101        21             101010     42             111111     63             1010100   84

10110        22             101011     43             1000000   64             1010101   85

10111        23             101100     44             1000001   65             1010110   86

11000        24             101101     45             1000010   66             1010111   87

11001        25             101110     46             1000011   67             1011000   88

11010        26             101111     47             1000100   68             1011001   89

11011        27             110000     48             1000101   69             1011010   90

11100        28             110001     49             1000110   70             1011011   91

11101        29             110010     50             1000111   71             1011100   92

11110        30             110011     51             1001000   72             1011101   93

11111        31             110100     52             1001001   73             1011110   94

100000     32              110101     53             1001010   74              1011111   95

100001     33              110110     54             1001011   75              1100000   96

100010     34              110111     55             1001100   76              1100001   97

100011     35              111000     56             1001101   77              1100010   98

100100     36              111001     57             1001110   78              1100011   99

                                                                                                  1100100 100¹

GPS Time Conversions

The following sections provide examples for converting to and from GPS Time.

GPS Time of Week to Day of Week with Time of Day

The value given for GPS Time of Week represents the number of seconds into the week. Therefore, to determine the day and time from that value, calculations are performed to break down the number of seconds into day, hour, minute, and second values.

For example, starting with a GPS Time of Week of 511200 seconds, the calculations are done as follows:

511200 seconds:

   Day of Week   511200 / 86400 seconds per day                       5.916666667 days

   Hour               0.916666667 x 86400 / 3600 seconds per hour   22.0000 hours

   Minute            0.000 x 3600 / 60 seconds per minute                0.000 minutes

   Second           0.000 x 60 seconds per minute                          0.000 seconds

Therefore, 511200 seconds represents day 5 (Thursday) + 22 hours, 0 minutes, 0 seconds into Friday.

Calendar Date to GPS Time

Converting a calendar date to GPS Time is calculated as shown in the following example, using the calendar date 13:30 hours, January 28, 2005.

Years from January 6, 1980 to January 28, 2005                                       25 years

Number of days in 25 years (25 years x 365 days/year)                            9,125 days

Add one day for each leap year (a year which is divisible by 4 but not
by 100, unless it is divisible by 400 as every 100 years a leap year isskipped)                                                                                         +   7 days

Add days from January 6 to January 27 (January 28th is not finished)    +   22 days

Total days                                                                                         =   9,154 days

Total number of seconds                                              =   790,905,600 seconds
(9154 days x 86400 seconds/day)                  

Total number of weeks                                                 =   1307.714285 weeks
(790,905,600 seconds / 604,800 seconds/week)  

Days into week (0.714285 x 7 days/week)                                          5 days

Number of seconds in 5 days (5 days x 86400 seconds/day)                 432,000 seconds

Add number of seconds into the 6th day, January 28th (13.5 hours
x 3600 seconds/hour)                                                                   +   48,600 seconds

Total seconds into week                                                                =   480,600 seconds

The resulting value for GPS Time is Week 1307, 480,600 seconds.

¹ These binary to decimal equivalents only go up to decimal 100 for the purpose of example. Please use a calculator for other conversions.