Latitude and Longitude Coordinate Converter

Tool Introduction

This "Latitude and Longitude Coordinate Converter" is a free online tool designed to provide users with convenient and efficient geographic coordinate system conversion services. It supports high-precision bidirectional conversion between WGS84 (Global Positioning System GPS standard coordinate system), GCJ02 (Chinese mainland encrypted Mars coordinate system), and BD09 (Baidu Map coordinate system). Whether you are engaged in map development, location services, geographic data analysis, or simply need to solve coordinate compatibility issues between different maps or positioning devices, this tool can help you ensure the accuracy of geographic location information.

How to Use

1. Select Conversion Type: First, on the tool interface, select your current "Source Coordinate System" and the "Target Coordinate System" you wish to convert to, for example: convert from WGS84 to GCJ02.
2. Enter Coordinate Data: In the specified input box, accurately fill in the longitude and latitude values to be converted. Please ensure the input format is a decimal floating-point number and maintain sufficient precision, for example: longitude 116.407440, latitude 39.904210.
3. Execute Conversion Operation: Click the "Convert" button, and the tool will immediately calculate based on the selected coordinate system and input data.
4. Get Conversion Results: After successful conversion, the system will display the converted longitude, latitude, and possibly the original coordinates and target coordinate system identifiers in the result area, making it convenient for you to copy and use directly.

Frequently Asked Questions

• Q: Which common coordinate systems does this converter support for mutual conversion?
  A: We support high-precision bidirectional conversion among WGS84 (GPS devices and international standard), GCJ02 (commonly used in mainland China, such as Gaode, Tencent Maps), and BD09 (Baidu Map exclusive) three major mainstream coordinate systems.
• Q: What are the differences between WGS84, GCJ02, and BD09 coordinate systems?
  A: WGS84 is a globally used geographic coordinate system, typically adopted by GPS devices. GCJ02 (Mars coordinate system) is an encrypted coordinate system stipulated by Chinese surveying and mapping departments for use in mainland China, which applies a non-linear offset based on WGS84. BD09 (Baidu coordinate system) is an encrypted offset again performed by Baidu Map for its own services based on GCJ02. Therefore, when using map services in mainland China, it is essential to pay attention to the corresponding relationship of coordinate systems to avoid positioning deviations.
• Q: What is the accuracy of the conversion results, and can they be used for commercial purposes?
  A: This tool uses industry-recognized coordinate conversion algorithms to provide high-precision conversion results. The conversion results can be used for various commercial and non-commercial scenarios such as map development, data analysis, and location services. However, for extremely strict surveying or military applications, it is still recommended to use professional-grade surveying equipment and software.

Coordinate System Offset Principle

In mainland China, to ensure the security of geographic information, the state stipulates that all publicly released maps and positioning services must use encrypted geographic coordinate data. This is the background for the creation of the GCJ02 coordinate system (also known as the Mars coordinate system). GCJ02 is formed by applying a non-linear offset to international standard WGS84 coordinates through a set of national confidential algorithms. This means that a WGS84 coordinate point, when displayed directly on a map in mainland China, will show an offset. Baidu Map, based on this, for the needs of its own services, again performed a secondary encrypted offset on GCJ02 coordinates, forming the BD09 coordinate system. Therefore, from WGS84 to GCJ02, and then to BD09, each conversion is a regular coordinate offset process, aimed at protecting geographic information data from being directly used for surveying or leakage, ensuring national geographic information security.

Notes

• Please ensure that the input longitude and latitude values are decimal floating-point numbers and maintain sufficient precision, for example: at least 6 decimal places.
• In mainland China, map service providers (such as Gaode, Tencent, Baidu) use different coordinate systems (GCJ02 or BD09). Therefore, when performing map development or positioning, please be sure to select the correct coordinate system for conversion according to the actual situation to avoid position deviation.
• The conversion results of this tool are intended to provide high-precision reference, but due to differences in algorithm implementation details and data sources, in a very small number of scenarios or extreme geographical locations, there may be tiny differences.