Coordinate Converter

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Source system

Source coordinate

Conversion results

Coordinate system	Decimal (lng,lat)	DMS (lng,lat)
WGS84 (input) International standard, GPS / Google Maps overseas	`116.404000,39.915000`	`116°24'14.4"E 39°54'54.0"N`
GCJ02 Mars coordinates, Amap / Tencent / Google in mainland China	`116.410244,39.916404`	`116°24'36.9"E 39°54'59.1"N`
BD09 Baidu coordinates, Baidu Maps	`116.416627,39.922700`	`116°24'59.9"E 39°55'21.7"N`
CGCS2000 China 2000 national geodetic, equivalent to WGS84 for civilian use	`116.404000,39.915000`	`116°24'14.4"E 39°54'54.0"N`

Coordinate systems

WGS84: World Geodetic System; the international standard, used by Google Maps overseas
GCJ02: Mars coordinate system, encrypted from WGS84; used by Google in mainland China, Amap, and Tencent Maps
BD09: Baidu coordinate system, secondarily encrypted from GCJ02
CGCS2000: China Geodetic Coordinate System 2000, equivalent to WGS84 at civilian precision

Pick a coordinate: Amap · Baidu · Tencent

Central meridian reference (Gauss-Krüger zones)

China uses the Gauss-Krüger projection with 6-degree and 3-degree zones. Zone number for 3-degree zones = local central meridian ÷ 3; for 6-degree zones = (local central meridian + 3) ÷ 6.

6-degree zones

Zone	Longitude range	Central meridian
13	72°E-78°E	75°E
14	78°E-84°E	81°E
15	84°E-90°E	87°E
16	90°E-96°E	93°E
17	96°E-102°E	99°E
18	102°E-108°E	105°E
19	108°E-114°E	111°E
20	114°E-120°E	117°E
21	120°E-126°E	123°E
22	126°E-132°E	129°E
23	132°E-138°E	135°E

3-degree zones

Zone	Longitude range	Central meridian
25	73.5°E-76.5°E	75°E
26	76.5°E-79.5°E	78°E
27	79.5°E-82.5°E	81°E
28	82.5°E-85.5°E	84°E
29	85.5°E-88.5°E	87°E
30	88.5°E-91.5°E	90°E
31	91.5°E-94.5°E	93°E
32	94.5°E-97.5°E	96°E
33	97.5°E-100.5°E	99°E
34	100.5°E-103.5°E	102°E
35	103.5°E-106.5°E	105°E
36	106.5°E-109.5°E	108°E
37	109.5°E-112.5°E	111°E
38	112.5°E-115.5°E	114°E
39	115.5°E-118.5°E	117°E
40	118.5°E-121.5°E	120°E
41	121.5°E-124.5°E	123°E
42	124.5°E-127.5°E	126°E
43	127.5°E-130.5°E	129°E
44	130.5°E-133.5°E	132°E
45	133.5°E-136.5°E	135°E

Coordinate conversion helps move data between WGS84, GCJ-02, BD-09, CGCS2000, and projected coordinate systems. It is used for map markers, route migration, data cleanup, and platform integration.

Before converting, identify whether the source data comes from GPS, Chinese map providers, Baidu Maps, or a projected coordinate system. A wrong source system can shift points by hundreds of meters.

FAQ

What is the difference between WGS84 and GCJ-02?expand_more

WGS84 is common for raw GPS data, while GCJ-02 is used by many mainland China map services and includes an offset.

Why is the converted point still shifted?expand_more

The source system may be wrong, longitude and latitude may be reversed, or the data may have already been converted.

Should batch results be checked manually?expand_more

Yes. Sample checks are recommended for production data, cross-city datasets, and provider migration.