Coordinate Distance Inputs
Enter decimal-degree coordinates. The page calculates a direct Earth-surface distance.
Example Data Table
| Location | Latitude | Longitude | Purpose |
|---|---|---|---|
| New York | 40.7128 | -74.0060 | Origin record |
| Los Angeles | 34.0522 | -118.2437 | Destination record |
| Mean Earth radius | 6,371.0088 km | General surface-distance model | |
Formula Used
The default option uses the Haversine formula. It measures the central angle between two geographic points. The final surface distance equals the chosen radius times that angle.
a = sin²(Δφ ÷ 2) + cos(φ₁) × cos(φ₂) × sin²(Δλ ÷ 2)
c = 2 × atan2(√a, √(1 − a))
d = R × c
Here, φ is latitude in radians, λ is longitude in radians, R is the selected radius, c is the central angle, and d is the calculated surface distance.
How to Use This Calculator
- Enter clear names for the start and end records.
- Enter each latitude and longitude in decimal degrees.
- Choose a radius preset or provide a custom radius.
- Select a calculation method and preferred result unit.
- Set the decimal precision needed for your report.
- Select Calculate Distance. The result appears above the form.
- Review the alternate units and copy the matching SQL query when needed.
Understanding SQL Server Distance Calculations
Distance calculations connect database records with real physical space. A coordinate pair describes a position using latitude and longitude. Latitude measures north or south position. Longitude measures east or west position. A database can store these values for offices, vehicles, sensors, customers, or field equipment. The calculator converts two coordinate pairs into a direct surface distance.
The Haversine method treats Earth as a sphere. It uses angles rather than flat map coordinates. This matters because latitude and longitude sit on a curved surface. A straight calculation on a flat grid becomes less accurate across long routes. The method measures the shortest path along Earth's surface. This path is called a great-circle distance.
A radius value controls the final result. The average Earth radius works for most planning tasks. An equatorial radius fits calculations near the equator. A polar radius fits calculations near the poles. You can also enter a custom radius. This helps when modeling another planet, a test sphere, or a specialized engineering assumption. The formula first finds the central angle. It then multiplies that angle by the chosen radius.
SQL Server can perform the same calculation inside a query. This is useful when a table contains many coordinate records. A query can compare each stored location with a selected origin. The result can support distance sorting, nearby searches, geofence screening, and location reports. The included query preview uses numeric variables and trigonometric functions. It keeps the input values visible for review.
Always confirm coordinate order before calculating. The calculator expects latitude first and longitude second. Latitude must stay between minus ninety and ninety degrees. Longitude must stay between minus one hundred eighty and one hundred eighty degrees. A reversed pair can produce a believable but incorrect distance. Decimal degrees are the format for web maps and geographic datasets.
Choose output units that match the task. Kilometres work well for regional planning. Miles suit many road and customer reports. Metres and feet help local engineering work. Nautical miles can help aviation and marine studies. The result panel also shows the central angle. This value is useful when comparing distances under different radius assumptions.
The calculation returns a surface distance, not driving distance. Roads, terrain, traffic rules, and route design can make a real journey longer. It also does not calculate altitude change. For local work over short ranges, a simple flat approximation may be acceptable. For broad geographic ranges, the spherical method is usually stronger. High precision surveying may require an ellipsoidal model and professional geodesic tools.
Use clean data to get dependable results. Remove impossible coordinates before saving records. Store latitude and longitude in decimal fields with adequate precision. Keep the same datum across every source. WGS 84 is common for coordinates. Test the query with known city pairs. Then compare results against a trusted map or geospatial service. This calculator gives a starting point for distance analysis.
Frequently Asked Questions
What does this calculator measure?
It measures the shortest path over a spherical surface between two latitude and longitude pairs. It does not calculate roads, flight plans, or walking routes.
Which coordinate format is required?
Use decimal degrees. Enter latitude first, then longitude. North and east are positive. South and west are negative.
Why is the Haversine method useful?
It remains dependable for broad geographic distances because it models Earth as a curved surface. It is commonly used for location search and reporting.
When should I use spherical cosine?
Use it when you want a compact trigonometric alternative. For most normal coordinates, it closely matches Haversine results. Haversine is often preferred for very short distances.
What Earth radius should I choose?
Use the mean radius for general work. Choose equatorial or polar values for a different spherical assumption. A custom radius supports other planets or test models.
Are miles and kilometres both available?
Yes. You can choose kilometres, miles, metres, feet, or nautical miles. The result details also display every supported unit.
Can the query run against a table?
Yes. Replace the sample variables with table columns or parameters. Keep the values in decimal degrees and use the same geographic datum for each record.
Does it include altitude?
No. This version calculates a two-dimensional surface distance. Add a separate vertical-distance calculation when altitude is relevant to your application.
Why can a road distance be longer?
Roads follow available paths, bridges, turns, traffic rules, and terrain. The calculator gives direct surface separation, which is usually shorter than a route.
How precise are the results?
Precision depends on coordinate quality and the Earth model. The displayed decimals control formatting. They do not create extra accuracy in the source data.
Can I download the calculation?
Yes. After calculating, download a CSV report or create a PDF. The query preview can also be copied for database testing.