Calculating The Latitude And Longitude Points Using Arcmap

What is Calculating Latitude and Longitude in ArcMap?

Calculating the latitude and longitude points using ArcMap refers to the process of identifying, defining, or converting the geographic coordinates of a specific location on Earth within the Esri ArcMap software. ArcMap, a core component of ArcGIS Desktop, is a powerful tool for working with maps and geographic information. Coordinates are fundamental to GIS, as they provide the reference system for all spatial data.

Latitude and longitude are part of a Geographic Coordinate System (GCS), which uses a three-dimensional spherical surface to define locations. Latitude lines run east-west but measure distance north or south of the equator, while longitude lines run north-south, measuring distance east or west of the Prime Meridian. These values are most commonly expressed in two formats: Decimal Degrees (DD) and Degrees, Minutes, Seconds (DMS). This calculator is designed to seamlessly convert between these two formats, a common task for GIS professionals who need to input data from various sources into ArcMap.

Coordinate Format Formula and Explanation

Understanding the mathematical relationship between DD and DMS is crucial for accurate data conversion and for calculating the latitude and longitude points using ArcMap.

Decimal Degrees (DD) to Degrees, Minutes, Seconds (DMS) Formula

The conversion from DD to DMS involves isolating the whole units (degrees) and converting the decimal part into minutes and seconds.

Degrees (D) = Integer part of the DD value.
Minutes (M) = Integer part of ((DD – D) * 60).
Seconds (S) = (((DD – D) * 60) – M) * 60.

Degrees, Minutes, Seconds (DMS) to Decimal Degrees (DD) Formula

The conversion from DMS to DD involves adding the fractions of degrees represented by the minutes and seconds.

DD = Degrees + (Minutes / 60) + (Seconds / 3600).
The sign of the DD value is determined by the hemisphere (South for latitude and West for longitude are negative).

Variable Definitions for Coordinate Conversion
Variable	Meaning	Unit	Typical Range
DD (Latitude)	Decimal Degrees for Latitude	Degrees	-90 to +90
DD (Longitude)	Decimal Degrees for Longitude	Degrees	-180 to +180
Degrees	The whole degree component	Degrees (°)	0-90 (Lat), 0-180 (Lon)
Minutes	A unit of arc; 1/60th of a degree	Minutes (‘)	0-59
Seconds	A unit of arc; 1/60th of a minute	Seconds (“)	0-59.99…

Practical Examples

Example 1: Convert New York City from DD to DMS

Let’s convert the approximate coordinates of New York City into DMS format, a common step when calculating the latitude and longitude points using ArcMap from a list.

Input Latitude (DD): 40.7128
Input Longitude (DD): -74.0060
Calculation (Latitude):
- Degrees = 40
- Minutes = Integer((40.7128 – 40) * 60) = Integer(42.768) = 42
- Seconds = ((40.7128 – 40) * 60 – 42) * 60 = 45.648
Result: 40° 42′ 45.648″ N, 74° 0′ 21.6″ W

Example 2: Convert Paris from DMS to DD

If you have coordinates from a survey map in DMS, you need to convert them to DD to use them in many digital GIS functions.

Input: 48° 51′ 24″ N, 2° 21′ 3″ E
Calculation (Latitude):
- DD = 48 + (51 / 60) + (24 / 3600) = 48 + 0.85 + 0.00667 = 48.85667
Result Latitude (DD): 48.8567
Result Longitude (DD): 2.3508

How to Use This Coordinate Converter Calculator

Using this tool is straightforward and designed to assist with your ArcMap projects.

Select your Conversion Type: Choose whether you want to convert from DD to DMS or DMS to DD using the corresponding section of the calculator.
Enter Your Coordinates:
- For DD to DMS, input the latitude and longitude in the decimal format. Use negative values for South and West hemispheres.
- For DMS to DD, input the degrees, minutes, and seconds into their respective fields and select the correct hemisphere (N/S, E/W) from the dropdown.
Calculate: Click the “Convert” button.
Interpret Results: The primary result will be displayed prominently, along with intermediate values used in the calculation. The chart will also update to visualize the components. This process is key to successfully calculating the latitude and longitude points using arcmap.

Key Factors That Affect Coordinate Calculations in ArcMap

When calculating the latitude and longitude points using ArcMap, several factors are critical for accuracy.

Geographic Coordinate System (GCS): This defines how locations are identified on a sphere. Different GCS use different spheroids and can result in slightly different coordinates for the same point.
Datum: A datum (like WGS 1984 or NAD 1983) is a reference frame for measuring locations. A mismatch in datums between data layers is a common source of error. For help, see our guide on Choosing the Right Datum.
Projected Coordinate System (PCS): Unlike a GCS, a PCS is a flat, two-dimensional representation of Earth. It’s crucial to understand if your data is geographic or projected. Learn more about Projected Coordinate System Explained.
Unit Accuracy: The number of decimal places in a DD coordinate or the seconds in DMS determines precision. Higher precision is needed for local-scale mapping than for global-scale.
Hemisphere Designation: Incorrectly assigning N/S or E/W (or the +/- sign in DD) will place your point in the wrong quadrant of the globe.
ArcMap’s ‘Go To XY’ Tool: This tool requires coordinates in a specific format. Using this converter ensures your data is ready for input.

Frequently Asked Questions (FAQ)

Why are my points showing up in the ocean when I add them to ArcMap?: This is a classic sign of reversed longitude/latitude or incorrect hemisphere signs. Longitude values in the Western hemisphere (like the Americas) must be negative, and forgetting this often places points off the coast of Africa.
What’s the difference between a GCS and a PCS?: A GCS (like WGS 1984) uses latitude and longitude on a spherical model of the Earth. A PCS (like UTM) projects that sphere onto a flat surface, using units like meters or feet. For more details, explore our GIS Data Conversion Basics.
How many decimal places should I use for Decimal Degrees?: It depends on your required accuracy: 4 decimal places is precise to about 11 meters, while 6 decimal places is precise to about 11 centimeters.
Can I enter spaces in the DMS fields?: No, please enter only numerical values for degrees, minutes, and seconds.
Does this calculator handle datum transformations?: No, this is a numerical format converter for DD and DMS. Datum transformations are more complex and require specialized GIS software like ArcMap’s Project tool.
How do I find coordinates directly in ArcMap?: You can see coordinates by hovering your mouse over the map view (displayed in the bottom-right corner) or by using the ‘Identify’ tool on a specific feature. You can also right-click a point feature class’s attribute table and use the ‘Calculate Geometry’ tool.
What is the “Go To XY” tool in ArcMap?: It’s a toolbar command that allows you to input x,y (longitude, latitude) coordinates to pan or zoom the map directly to that location.
Why does the chart show negative values?: The chart visualizes the raw components of the calculation. A negative value on the chart simply reflects the input coordinate (e.g., a negative longitude for the Western hemisphere).

Related Tools and Internal Resources

Expand your GIS knowledge with our other articles and tools.

Mastering ArcMap Layouts
Turn your data into a professional map presentation.
Introduction to Spatial Analysis
Learn the fundamentals of analyzing geographic patterns.
Georeferencing Imagery Tutorial
Align raster images with your map data.
Choosing the Right Datum
A critical guide to understanding and selecting datums.
Projected Coordinate System Explained
Dive deeper into how flat maps are made.
GIS Data Conversion Basics
An overview of converting between different GIS file types.

Latitude and Longitude Converter for ArcMap

Decimal Degrees (DD) to Degrees, Minutes, Seconds (DMS)

Degrees, Minutes, Seconds (DMS) to Decimal Degrees (DD)

Conversion Result