Coordinates Calculator — Free Online Coordinate Converter

How to Use the Coordinates Calculator

1. Enter the latitude: Type the latitude value in decimal degrees in the Latitude field. Northern hemisphere latitudes are positive numbers (e.g., 40.7128 for New York) and southern hemisphere latitudes are negative (e.g., -33.8688 for Sydney). The valid range is -90 to +90 degrees. If you have coordinates in DMS format, first convert the degrees, minutes, and seconds to a single decimal number: Decimal = Degrees + Minutes/60 + Seconds/3600.
2. Enter the longitude: Type the longitude value in decimal degrees in the Longitude field. Eastern hemisphere longitudes are positive (e.g., 139.6503 for Tokyo) and western hemisphere longitudes are negative (e.g., -74.0060 for New York). The valid range is -180 to +180 degrees. The calculator clips values outside these ranges to prevent invalid coordinates.
3. Review the coordinate formats: The results panel instantly displays your coordinates in three standard formats. Decimal Degrees (DD) shows the compact numeric format used in most digital applications. Degrees Minutes Seconds (DMS) shows the traditional cartographic format with degree, minute, and second symbols plus hemisphere letters. Degrees Decimal Minutes (DMM) shows the hybrid format popular in marine navigation and geocaching.
4. Note the hemisphere information: The bottom of the results panel identifies whether the location is in the Northern or Southern hemisphere (based on latitude sign) and Eastern or Western hemisphere (based on longitude sign). This helps verify that you entered the correct signs for your coordinates.

All results update instantly as you type. The calculator provides six decimal places of precision for DD format, two decimal places for DMS seconds, and four decimal places for DMM minutes, ensuring accuracy to within a fraction of a meter for any application.

Coordinate Conversion Formulas

Variables Explained

• DD (Decimal Degrees): The input coordinate as a single decimal number. This is the most computationally friendly format and is used by GPS systems, mapping APIs, and most digital tools. One degree equals approximately 111 km of latitude.
• |DD| (Absolute Value): The absolute value of the decimal degree, used in calculations to extract the degree, minute, and second components. The sign (positive or negative) is converted to the directional letter (N/S/E/W) in the output.
• Degrees: The whole number part of the coordinate, representing full degrees of arc. This is the integer portion obtained by taking the floor of the absolute decimal degree value.
• Minutes: Each degree contains 60 minutes of arc. The minutes value is extracted from the fractional part of the decimal degrees by multiplying by 60 and taking the floor. One minute of latitude equals approximately 1.852 km (one nautical mile).
• Seconds: Each minute contains 60 seconds of arc. Seconds are the finest subdivision and provide precision to approximately 31 meters per second of arc at the Equator. Seconds can include decimal places for sub-meter precision.
• Hemisphere Direction: Determined by the sign of the input: positive latitude is North (N), negative is South (S), positive longitude is East (E), and negative longitude is West (W).

Step-by-Step Example

Convert the coordinates of the Eiffel Tower (48.8584° N, 2.2945° E) from DD to DMS and DMM:

1. Latitude 48.8584: Degrees = 48, Remaining = 0.8584
2. Minutes = floor(0.8584 × 60) = floor(51.504) = 51
3. Seconds = (51.504 - 51) × 60 = 0.504 × 60 = 30.24"
4. DMS Latitude: 48° 51' 30.24" N
5. Decimal Minutes = 0.8584 × 60 = 51.5040'
6. DMM Latitude: 48° 51.5040' N
7. Longitude 2.2945: Degrees = 2, Minutes = floor(0.2945 × 60) = 17, Seconds = (17.67 - 17) × 60 = 40.20"
8. DMS Longitude: 2° 17' 40.20" E | DMM: 2° 17.6700' E

Practical Examples

Example 1: Lisa's Geocaching Adventure

Lisa receives geocache coordinates in DMM format: N 37° 47.5320', W 122° 25.3680' (near San Francisco). She needs to enter these into her mapping app, which only accepts decimal degrees. She manually calculates: latitude = 37 + 47.5320/60 = 37.7922, longitude = -(122 + 25.3680/60) = -122.4228. She verifies using this calculator by entering 37.7922 and -122.4228. The DMM output matches her original coordinates perfectly, confirming her conversion. She copies the DD values into her mapping app and drives to within 10 meters of the geocache.

Example 2: Captain Ahmed's Maritime Navigation

Captain Ahmed receives port coordinates in DMS format from a shipping manifest: 1° 17' 24.00" N, 103° 51' 0.00" E (Singapore). His electronic chart display uses decimal degrees. He enters the DD equivalent (1.29, 103.85) into this calculator to verify the DMS output matches the manifest. The calculator confirms: 1° 17' 24.00" N, 103° 51' 0.00" E. He also converts the departure port coordinates of Rotterdam (51° 55' 28.00" N, 4° 28' 40.00" E) and uses the Distance Between Cities Calculator with the DD values to compute the voyage distance.

Example 3: Dr. Rivera's Research Data Standardization

Dr. Rivera is a marine biologist compiling dolphin sighting locations from multiple research teams. Team A reports in DMS (28° 15' 36.00" N, 80° 36' 0.00" W), Team B in DD (27.9506, -80.4522), and Team C in DMM (N 28° 32.4000', W 80° 15.6000'). She uses this calculator to convert all coordinates to DD format for her GIS database. After entering each team's data and recording the DD output, she has a standardized dataset ready for spatial analysis. The conversion ensures all data points can be plotted accurately on the same map and analyzed using distance calculations in her research software.

Example 4: Tom Planning a Drone Survey

Tom is a surveyor planning a drone flight path over a construction site. The site plan specifies corner coordinates in DMS format: NE corner 34° 3' 18.00" N, 118° 14' 42.00" W and SW corner 34° 2' 54.00" N, 118° 15' 6.00" W. His drone flight planning software requires DD format. He enters each corner into the calculator and gets NE: (34.055, -118.245) and SW: (34.048333, -118.251667). The difference in latitude is 0.006667 degrees (about 740 meters) and in longitude is 0.006667 degrees (about 560 meters at this latitude). Tom uses these DD coordinates to program his drone's waypoints and calculates the site area using the Directions Calculator for bearing orientation.

Coordinate Precision Reference Table

Precision values are approximate and represent latitude distances. Longitude precision decreases toward the poles due to converging meridians.

Tips and Complete Guide

Choosing the Right Coordinate Format

Select the coordinate format that matches your downstream application. If you are importing coordinates into software, databases, or programming code, use Decimal Degrees (DD) because it is a single number per axis and avoids the complexity of degree, minute, and second separators. If you are reading coordinates from or writing them to nautical charts, land survey documents, or regulatory filings, use Degrees Minutes Seconds (DMS) because it is the traditional standard in cartography. If you are working with marine electronics, aviation flight plans, or geocaching, use Degrees Decimal Minutes (DMM) because these communities have standardized on this format. This calculator produces all three simultaneously, so you never need to choose one at the expense of losing the others.

Common Coordinate Systems and Datums

This calculator works with the standard geographic coordinate system (latitude/longitude) referenced to the WGS84 datum, which is the global standard used by GPS and most mapping services since the 1980s. Older maps and surveys may reference different datums such as NAD27 (North American Datum of 1927) or ED50 (European Datum 1950). Coordinates in different datums for the same physical location can differ by tens to hundreds of meters. If you are working with coordinates from older survey data, you may need a datum transformation before using this calculator. Modern GPS devices and online mapping services almost universally use WGS84, so coordinates from these sources are directly compatible with this tool.

Verifying Coordinate Accuracy

After converting coordinates, always verify the result by plotting the DD values on a mapping service to confirm the location is where you expect it to be. Common errors include transposing latitude and longitude (putting the north-south value where the east-west value should be), forgetting the negative sign for southern or western hemispheres, and misreading DMS notation (confusing minutes and seconds symbols). A quick visual check on a map catches these errors immediately. For critical applications like aviation, maritime navigation, or land surveying, always double-check converted coordinates against a known reference point before using them.

Common Mistakes to Avoid

• Entering longitude in the latitude field (or vice versa): Latitude ranges from -90 to +90 and longitude from -180 to +180. If you enter a value like 122 in the latitude field, the calculator will clip it to 90 because latitudes cannot exceed 90 degrees. Always enter latitude first, then longitude.
• Forgetting the negative sign: Locations in the Southern Hemisphere (e.g., Sydney, Buenos Aires) require negative latitudes. Locations in the Western Hemisphere (e.g., New York, Sao Paulo) require negative longitudes. Omitting the minus sign places the location in the wrong hemisphere entirely.
• Confusing the degree symbol with apostrophe or quote marks: In DMS notation, degrees use °, minutes use ' (single prime/apostrophe), and seconds use " (double prime/quote). Mixing these symbols when reading coordinates from a source document leads to incorrect conversions. This calculator uses standard notation in its output.
• Using coordinates from different datums without conversion: If your source coordinates are referenced to a datum other than WGS84, the plotted location may be offset by tens or hundreds of meters. Always confirm the datum before assuming coordinates are directly usable.
• Rounding too aggressively: For most travel purposes, four decimal places of DD are sufficient. But rounding to one or two decimal places introduces errors of 1 to 11 km, which could place you in the wrong town or on the wrong side of a river.

Frequently Asked Questions