Our checker connects a place, a coordinate pair and a map point. Search in either direction, check the position, then choose the notation or report you need.
Search for an address, postcode, city or landmark. If you already have coordinates, switch direction and enter latitude followed by longitude. Decimal degrees, degrees/minutes/seconds and decimal minutes are accepted; you do not have to convert your field notes first.
A name can refer to several places. Choose the matching search result and inspect its surroundings. Click the map or drag the marker when you need a different point. Your original coordinate remains the result even when its nearest mapped address is somewhere else.
Keep decimal degrees for everyday maps, or open the additional formats for DMS, DMM and a geo: link. Copy a pair, share this selected point or download a branded PNG, TXT, CSV or GeoJSON file. Review private locations before sharing them.
A park entrance, trailhead or beach access may be easier to describe with a point than a street address. Check that the marker is at the entrance people can actually use, then send a map link with a short written description.
Save the viewpoint you intend to visit, not merely the centre of a town. Bring the pair into our Golden Hour Calculator for light planning, or keep a coordinate report alongside your route notes. This checker does not plan a safe route.
Compare the Eiffel Tower, the Taj Mahal and Sydney Opera House. Notice how north/south changes the latitude sign and east/west changes longitude. Moving a marker makes those relationships visible without asking pupils to share their own location.
A small GeoJSON point is useful in a mapping project; CSV is convenient for a spreadsheet. Check the receiving program’s coordinate order before importing. GeoJSON writes longitude first, whereas this tool’s input fields deliberately put latitude first.
Find a coordinate from a place, or find a nearby mapped place from a coordinate. Search suggestions help narrow a name; dragging the marker selects a new point. An unavailable address or map tile does not remove a valid coordinate.
Use signed decimal degrees, DMS or DMM in either labelled field. A pasted pair uses latitude first. For decimal commas, separate the two values with a semicolon, such as 48,8584; 2,2945. We reject unclear formats rather than silently rearranging them.
Use my location requests the browser’s location permission. When available, the result includes the device’s capture time and reported accuracy radius. A quicker reading can appear before a refinement; a worse follow-up does not replace a better reading.
DD, DMS, DMM and the Geo URI describe the same selection. Conversions carry rounded seconds and minutes into the next unit. More displayed digits help reproduce the pair, but do not create additional real-world accuracy.
The shared link opens the selected pair in the current page language; it is not a live location tracker. PNG and text reports include context and ClockTools branding. CSV protects spreadsheet cells, and GeoJSON uses the standard longitude–latitude order.
The five most recent selections are stored in this browser, not in a user account. Reopening an old point does not turn it into a fresh GPS fix. Clear history removes this tool’s saved list; browser storage restrictions do not prevent a new lookup.
Latitude describes how far north or south a position lies relative to the equator. Its range is −90° to +90°. Longitude describes east or west relative to a reference meridian, with values from −180° to +180°. Together they locate a point on a reference surface; neither number describes a road, a floor in a building or whether you can reach the point.
Positive latitude means north, while negative means south. Positive longitude means east, while negative means west. A minus sign is therefore meaningful, not decoration. If a pair looks plausible but lands on another continent, check its signs and order before adding more decimal places. Zero is valid: 0° latitude is the equator and 0° longitude is the prime meridian.
For centuries, sailors could estimate latitude from the Sun and stars more readily than longitude. Longitude required comparing local time with time at a reference location. An error in the reference time became an error in east–west position, which made reliable marine timekeeping a practical navigation problem rather than an abstract mathematical puzzle.
In 1884, the International Meridian Conference adopted Greenwich as the common prime meridian. A shared starting line made charts, navigation and timekeeping easier to coordinate. Modern satellite-based reference systems do not place their zero line exactly on the historic telescope line at the Royal Observatory. Both belong to the history of measurement; modern GPS coordinates should be interpreted in their modern reference system.
When we paste a pair into a map today, we are using the outcome of that long effort to make observations comparable. A common datum and an agreed notation allow a photograph, a field note and a mapping application to refer to the same place without requiring each user to invent a local origin.
One degree contains 60 minutes, and one minute contains 60 seconds. To convert DMS to decimal degrees, add degrees + minutes ÷ 60 + seconds ÷ 3600, then apply the south or west sign to the complete result. Decimal minutes keep the degree whole and put the remaining fraction into minutes. These are angular units, not minutes and seconds of elapsed time.
For example, 48° 51′ 30″ N becomes 48.858333° to six decimal places. The same latitude is 48° 51.5000′ N in decimal minutes. If rounding produces 60 seconds, that becomes another minute; if a minute becomes 60, it becomes another degree. Our converter handles those carries so the displayed notation remains valid.
| Decimal degrees (DD) | Degrees, minutes, seconds | Decimal minutes (DMM) |
|---|---|---|
48.858333 | 48° 51′ 30″ N | 48° 51.5000′ N |
-33.850000 | 33° 51′ 00″ S | 33° 51.0000′ S |
-74.044500 | 74° 02′ 40.2″ W | 74° 02.6700′ W |
No. Precision is how finely a number is written; accuracy is how closely it represents the actual position. A carefully typed six-decimal pair can still point to the centre of a building instead of its entrance. A browser can also return a precise-looking number with a large uncertainty radius. Check the source and reported accuracy, not just the number of digits.
A degree of latitude spans roughly 111 kilometres, with some variation across Earth. Longitude spacing shrinks towards the poles because meridians meet there. At the equator, 0.000001° is approximately 0.11 metres in either direction; that is a notation interval, not a promise of centimetre-level positioning. Indoors, weak signals and device hardware can dominate the actual error.
Latitude remains valid all the way to ±90°, but the rectangular web map used here does not cover the poles. Its Mercator view stops near ±85.0511°. We keep polar coordinates available for copying and exporting rather than moving the marker to an incorrect latitude just to make it visible.
The antimeridian is another useful edge case: +180° and −180° longitude describe the same boundary. When you click a repeated world on the map, we bring the longitude back into the conventional range. Near this boundary, a small movement can switch the displayed sign without moving the point across the world. Map projection and coordinate notation are different things.
A map database may know a street, a building outline or a nearby named feature without knowing an entrance at your coordinate. Reverse lookup returns a mapped description associated with the area; it does not prove ownership, occupancy or access. In rural areas and on water, a usable coordinate may have no conventional address at all.
Keep the selected point and the address description separate. For a delivery or meeting, inspect the map and add practical directions. For legal boundaries, emergency response or surveying, use the relevant official service and qualified professionals. Our checker helps interpret and exchange coordinates; it does not certify a site.
We validate angular ranges and convert the chosen point between DD, DMS and DMM. Place searches and reverse lookups supply mapped descriptions; selecting the map changes the point. Device readings retain their own accuracy and capture time, when available. Reports state the source so an entered coordinate is not mistaken for a GPS measurement.
Map coverage, address descriptions and positioning accuracy have separate limits. A valid coordinate can lack an address or visible polar map coverage. Additional decimal places do not improve a device fix. Shared links and downloads contain the selected pair; they are not live tracking or survey certification.
If a place label or conversion appears wrong, report the page language, input notation, expected point and what you observed. Use a public example when possible and do not include private locations unnecessarily. We review reproducible input, formatting and display errors; mapping descriptions may require correction in the underlying map data.
Methodology and limitations · Corrections and feedbackOur fields and pasted pairs use latitude first, then longitude. GeoJSON exports follow its standard and use longitude first. Always check the receiving application instead of assuming every format uses the same order.
Yes. For example, enter 48° 51′ 30″ N in latitude and 2° 17′ 40″ E in longitude. You can also use decimal minutes or signed decimal degrees. Invalid minutes, seconds or contradictory hemisphere signs are rejected.
Yes, in either separate field. In a pasted pair, use a semicolon between decimal-comma values, for example 48,8584; 2,2945. An ambiguous comma-separated sequence is not guessed.
The browser selects the available positioning method, which can involve GPS, Wi-Fi or other device services. Permission is required. Device accuracy and capture time are shown when provided; entering or searching for a point does not require location permission.
Names and postcodes can refer to multiple areas. Add a city or country, choose the matching result and inspect the map before sharing. A search result is a mapped place, not necessarily your present position.
No. It opens one selected coordinate pair. It does not transmit later movements. Anyone with the link can read that pair, so avoid sharing a private address or sensitive location unintentionally.
Map images and address searches can fail independently of the coordinate calculation. You can still copy, convert and download a valid pair. Very high polar latitudes are intentionally outside this map’s coverage.
Not as a certified measurement. Browser positioning, mapped landmarks and manual markers have different uncertainties. Surveying and legal boundary work require appropriate reference systems, instruments and professional verification.