About

Coordinate format mismatches cause real problems. Survey data arrives in DMS (degrees, minutes, seconds). Your mapping API expects decimal degrees. Geotagged photographs store GPS data as EXIF rational fractions like 4045/100. A single sign error or hemisphere omission places your point in the wrong ocean. This tool converts between DMS, decimal degrees, and EXIF rational notation with full precision. It applies the standard decomposition D + M60 + S3600 and negates the result for South or West hemispheres. Output includes GeoJSON-compliant [lon, lat] ordering per RFC 7946. Precision is limited only by IEEE 754 double-precision floating point (~15 significant digits, sub-millimeter at Earth's surface).

Formulas

The conversion from degrees-minutes-seconds to decimal degrees uses the sexagesimal decomposition:

DD = D + M60 + S3600

Where D = whole degrees, M = arc-minutes (0 - 59), S = arc-seconds (0 - 59.9999). The result is negated when the hemisphere reference is South or West:

DD_signed =

{

+DD if ref ∈ {N, E}−DD if ref ∈ {S, W}

For EXIF rational fractions (e.g., 4045/100), the numerator is divided by the denominator before applying the formula. The reverse conversion extracts components:

D = floor(|DD|)
M = floor((|DD| − D) × 60)
S = (|DD| − D − M60) × 3600

GeoJSON (RFC 7946) requires coordinates in [longitude, latitude] order, the reverse of conventional [lat, lon] notation.

Reference Data

Location	Latitude DMS	Longitude DMS	Lat Decimal	Lon Decimal
Statue of Liberty, USA	40° 41′ 21.24″ N	74° 2′ 40.08″ W	40.689233	−74.044467
Eiffel Tower, France	48° 51′ 29.88″ N	2° 17′ 40.20″ E	48.858300	2.294500
Sydney Opera House	33° 51′ 24.37″ S	151° 12′ 54.43″ E	−33.856769	151.215119
Machu Picchu, Peru	13° 9′ 47.00″ S	72° 32′ 44.00″ W	−13.163056	−72.545556
Mount Fuji, Japan	35° 21′ 38.70″ N	138° 43′ 38.50″ E	35.360750	138.727361
Great Pyramid of Giza	29° 58′ 45.03″ N	31° 8′ 3.69″ E	29.979175	31.134358
Christ the Redeemer	22° 57′ 5.70″ S	43° 12′ 38.70″ W	−22.951583	−43.210750
Colosseum, Rome	41° 53′ 24.61″ N	12° 29′ 32.39″ E	41.890169	12.492331
Taj Mahal, India	27° 10′ 29.39″ N	78° 2′ 31.66″ E	27.174831	78.042128
Stonehenge, UK	51° 10′ 43.84″ N	1° 49′ 34.28″ W	51.178844	−1.826189
Table Mountain, SA	33° 57′ 21.42″ S	18° 24′ 21.47″ E	−33.955950	18.405964
Angkor Wat, Cambodia	13° 24′ 44.97″ N	103° 52′ 0.22″ E	13.412492	103.866728
Niagara Falls, Canada	43° 4′ 42.00″ N	79° 4′ 29.00″ W	43.078333	−79.074722
North Pole	90° 0′ 0.00″ N	0° 0′ 0.00″ E	90.000000	0.000000
South Pole	90° 0′ 0.00″ S	0° 0′ 0.00″ E	−90.000000	0.000000

Frequently Asked Questions

RFC 7946 mandates [longitude, latitude, altitude] order to align with the mathematical convention where x (easting/longitude) precedes y (northing/latitude). Most mapping APIs (Leaflet, Mapbox) expect this order. Swapping them places your point at a mirrored location across the equator-prime-meridian intersection.

Camera firmware stores DMS components as unsigned rational numbers (numerator/denominator pairs) to avoid floating-point precision loss. The value 4045/100 equals 40.45 arc-seconds exactly. When parsing, always divide numerator by denominator before applying the DMS-to-decimal formula.

At the equator, 1 degree of latitude ≈ 111.32 km. Six decimal places yield ~0.11 m resolution. Eight decimal places reach ~1.1 mm. Beyond 8 decimals, IEEE 754 double-precision rounding exceeds GPS receiver accuracy (~2 - 5 m civilian).

No. Valid DMS ranges are: degrees 0 - 90 (latitude) or 0 - 180 (longitude), minutes 0 - 59, seconds 0 - 59.9999.... Values of 60 seconds should roll over into the next minute. This tool validates these ranges and flags out-of-bound inputs.

Negative latitude indicates South hemisphere. Negative longitude indicates West hemisphere. When converting decimal to DMS, this tool automatically assigns the correct hemisphere letter (N/S for latitude, E/W for longitude) based on the sign, then uses the absolute value for the DMS components.

The International Date Line sits at ±180°. Values like 181° E are technically equivalent to 179° W (181 − 360 = −179). This tool accepts ±180 and flags values outside that range. Some datasets use 0 - 360 notation; subtract 360 if your value exceeds 180.