本文翻译自：What is the maximum length of latitude and longitude?

How long can latitude and longitude be? 经度和纬度能达到多长时间？

I am getting very long lengths sent by a Windows Phone device: Windows Phone设备发送的长度越来越长：

This is exceeding my table column size and I am getting errors. 这超出了我的表列大小，并且出现错误。

参考：https://stackoom.com/question/14ZgG/纬度和经度的最大长度是多少

The valid range of latitude in degrees is -90 and +90 for the southern and northern hemisphere respectively. 南半球和北半球的有效纬度范围分别是-90和+90 。 Longitude is in the range -180 and +180 specifying coordinates west and east of the Prime Meridian, respectively. 经度在-180和+180范围内，分别指定本初子午线以西和以东的坐标。

For reference, the Equator has a latitude of 0°, the North pole has a latitude of 90° north (written 90° N or +90°), and the South pole has a latitude of -90°. 作为参考， 赤道的纬度为0°， 北极的纬度为北90°（写为90°N或+ 90°）， 南极的纬度为-90°。

The Prime Meridian has a longitude of 0° that goes through Greenwich, England. 本初子午线经英格兰格林威治的经度为0°。 The International Date Line (IDL) roughly follows the 180° longitude. 国际日期变更线（IDL）大致遵循180度经度。 A longitude with a positive value falls in the eastern hemisphere and negative value falls in the western hemisphere. 东半球为正值的经度，西半球为负值的经度。

Decimal degrees precision 小数度精度

Six (6) decimal places precision in coordinates using decimal degrees notation is at a 10 cm (or 0.1 meter) resolution. 使用十进制度数表示法的坐标中六（6）个小数位精度为10 cm（或0.1米）。 Each .000001 difference in coordinate decimal degree is approximately 10 cm in length. 坐标十进制度的每个.000001差异长度约为10厘米。 For example, the imagery of Google Earth and Google Maps is typically at the 1 meter resolution, and some places have a higher resolution of 1 inch per pixel. 例如，“ Google地球”和“ Google地图”的图像通常为1米的分辨率，有些地方的分辨率为每像素1英寸。 One meter resolution can be represented using 5 decimal places so more than 6 decimal places is extraneous for that resolution. 一米的分辨率可以使用5个小数位表示，因此该分辨率不需要6个小数位。 The distance between longitudes at the equator is the same as latitude, but the distance between longitudes reaches zero at the poles as the lines of meridian converge at that point. 赤道上的经度距离与纬度相同，但是当子午线在该点收敛时，经度之间的距离在极点处达到零。

If Latitude value is reported as -6.3572375290155 or -63.572375290155 then you could round-off and store up to 6 decimal places for 10 cm (or 0.1 meter) precision. 如果纬度值报告为-6.3572375290155或-63.572375290155，则可以四舍五入并存储最多6个小数位，精度为10 cm（或0.1米）。

For millimeter (mm) precision then represent lat/lon with 8 decimal places in decimal degrees format. 对于毫米（mm）精度，则以十进制度数表示小数点后8位的经/纬度。 Since most applications don't need that level of precision 6 decimal places is sufficient for most cases. 由于大多数应用程序不需要那种精确度的小数点后6位就可以满足大多数情况。

In the other direction, whole decimal degrees represents a distance of ~111 km (or 60 nautical miles) and a 0.1 decimal degree difference represents a ~11 sq. Km area. 在另一个方向上，整个十进制度表示的距离约为111公里（或60海里），而十进制度差的0.1表示面积约为11平方公里。

Here is a table of # decimal places difference in latitude with the delta degrees and the estimated distance in meters using 0,0 as the starting point. 这是一张＃纬度差异的小数位数表格，其中以度数为单位，以0,0为起点的估算距离（以米为单位）。

Degrees-minute-second (DMS) representation 度-分-秒（DMS）表示

For DMS notation 1 arc second = 1/60/60 degree = ~30 meter length and 0.1 arc sec delta is ~3 meters. 对于DMS表示法，1弧秒= 1/60/60度=约30米长，0.1弧秒增量为〜3米。

Example: 例：

1 arc minute = 1/60 degree = ~2000m (2km) 1弧分= 1/60度=〜2000m（2km）

UPDATE: Here is an amusing blog post about coordinate precision. 更新：这是一篇有关坐标精度的有趣博客文章 。

Latitude : max/min +90 to -90 纬度 ：最大/最小+90至-90

Longitude : max/min +180 to -180 经度 ：最高/最低+180至-180

Latitude maximum in total is: 9 (12.3456789), longitude 10 (123.4567890), they both have maximum 7 decimals chars (At least is what i can find in Google Maps ), 纬度最大值总计为：9（12.3456789），经度10（123.4567890），它们都具有最大7个小数点字符（至少是我在Google Maps中可以找到的字符），

For example, both columns in Rails and Postgresql looks something like this: 例如，Rails和Postgresql中的两列都看起来像这样：

Valid longitudes are from -180 to 180 degrees. 有效经度为-180至180度。

Latitudes are supposed to be from -90 degrees to 90 degrees, but areas very near to the poles are not indexable. 纬度应该在-90度到90度之间，但是极点附近的区域无法转位。

So exact limits, as specified by EPSG:900913 / EPSG:3785 / OSGEO:41001 are the following: 因此，EPSG：900913 / EPSG：3785 / OSGEO：41001指定的确切限制如下：

The ideal datatype for storing Lat Long values in SQL Server is decimal(9,6) 在SQL Server中存储Lat Long值的理想数据类型是十进制（9,6）

As others have said, this is at approximately 10cm precision, whilst only using 5 bytes of storage. 正如其他人所说，这大约是10厘米的精度，而仅使用5字节的存储空间。

eg CAST(123.456789 as decimal(9,6)) as [LatOrLong] 例如CAST(123.456789 as decimal(9,6)) as [LatOrLong]