Coordinates
GPS coordinates converter: one spot, every format.
The same point on earth can be written four different ways. Here is what each coordinate format means, how to convert between them by hand, and how to read your own position in all four without doing any math.
To convert GPS coordinates, you first need to know which of the four common formats you are starting from and which one you need. Decimal degrees, degrees-minutes-seconds, degrees and decimal minutes, and the MGRS military grid all describe the exact same point on earth. They just write it differently. Once you can read all four, converting is either simple arithmetic or a job for a tool that does it for you.
Most people hit this when someone hands them a position in a format their app will not take. A boater reads out decimal minutes when your maps app wants decimal degrees, or a search team calls a grid you have never seen. Here is how each format works, how to move between them, and how to skip the conversion entirely for your own location.
The four coordinate formats
Every spot in the examples below is the same single point. Notice how the numbers change shape from one format to the next while pointing at the identical place.
Decimal degrees
DD38.8977, -77.0365
One number for latitude, one for longitude, each with a decimal. A minus sign means south or west. This is what Google Maps, Apple Maps, and most websites accept, and it is the easiest to copy and paste.
Degrees, minutes, seconds
DMS38°53'52"N, 77°02'11"W
The old-school format, read like a clock: each degree splits into 60 minutes, and each minute into 60 seconds. A letter (N, S, E, W) gives the direction instead of a sign. You see it on paper maps and nautical charts.
Degrees and decimal minutes
DDM38°53.86'N, 77°02.19'W
A middle ground: whole degrees, then minutes with a decimal instead of seconds. Common in boating and aviation, where it is the standard on most marine GPS units.
Military grid
MGRS18S UJ 23408 06479
A letter-and-number code instead of degrees, built on the UTM grid the military uses. It is not latitude and longitude at all, so you cannot convert it in your head. Here is how MGRS works in full.
How to convert between them
The conversions split into two groups: the three degree formats, which are simple arithmetic, and MGRS, which is not.
Decimal degrees, decimal minutes, and degrees-minutes-seconds are the same number written three ways, so you can move between them with a calculator. Take the latitude 38.8977:
- The whole part, 38, stays as the degrees.
- Multiply the decimal part by 60: 0.8977 × 60 = 53.86 minutes. That gives you DDM,
38°53.86'. - Take the decimal of that, 0.86, and multiply by 60 again: 0.86 × 60 = 52 seconds. That gives you DMS,
38°53'52".
Run it backward to go the other way: seconds divided by 60, plus minutes, divided by 60, plus degrees. The sign or the N/S/E/W letter carries the direction through every step.
MGRS is the exception. It comes from projecting the globe onto a flat grid, so there is no quick formula in your head. To convert a grid reference to or from latitude and longitude, you need a tool or an app that understands the grid. That is true in both directions, which is exactly why having all four formats on one screen is so useful.
Convert your own location with no math
Here is the shortcut most people miss. If the coordinates you need to convert are your own position, you never have to convert anything. An app that reads your GPS once and shows all four formats at the same time has already done it for you.
LOC8 displays where you are standing in decimal degrees, degrees and decimal minutes, degrees-minutes-seconds, and the MGRS grid, and lets you switch between them with a tap. Whatever format the person on the other end uses, a friend with Google Maps, a boater, a 911 operator, or a search and rescue team, it is already on your screen, ready to read out or copy.
LOC8 is not a paste-in converter for random coordinates. It is faster than one for the case that actually comes up in the field: your exact position, shown in all four formats at once, next to your full address and nearest cross street. No account, and it works offline.
Convert coordinates someone gave you
When the coordinates belong to someone else, a position read to you over the radio or pulled off a chart, you have two clean options:
- For the three degree formats, do the arithmetic above, or paste the numbers into a free online coordinate converter. To drop a decimal-degrees pair onto a map, type it straight into the Apple Maps or Google Maps search bar and the pin lands on it.
- For MGRS, use a tool that reads the grid, since there is no by-hand shortcut. Many mapping apps for the field accept an MGRS string and place it for you.
The golden rule either way: make sure both ends agree on the format before you start. Half of all "the coordinates are wrong" problems are really a format mismatch, not a bad reading.
Mistakes that send people to the wrong place
Coordinates are precise, so a small slip is a big miss. Watch for these when you convert:
- Dropping the sign or the letter. Forgetting the minus on a west longitude, or swapping N for S, flips you to the opposite side of the planet. Decimal degrees use a minus; the other formats use a direction letter, and it has to survive the conversion.
- Mixing formats. Pasting a degrees-minutes-seconds value into a box that expects decimal degrees gives a wildly wrong spot. Convert first, then paste.
- Swapping latitude and longitude. Latitude always comes first and only runs from -90 to 90; longitude is second and runs to 180. If your "latitude" is over 90, you have them backward. More on reading a pair in the latitude and longitude guide.
Which format to use when
You convert to a format because the person receiving it expects it. Match the receiver:
- Decimal degrees for maps apps, websites, and texting a friend a spot to meet.
- Degrees and decimal minutes for marine and aviation, where it is the default on the equipment.
- Degrees-minutes-seconds for paper maps and nautical charts.
- MGRS for the military, search and rescue, and wildland fire crews.
Send the format they already work in, and they paste it straight in with no conversion on their end, which is one less place for a digit to go missing.
Every format, no conversion
Your position in decimal degrees, decimal minutes, degrees-minutes-seconds, and MGRS, the second you open the app. Tap to switch, copy, or share. Works offline. No account.
Common questions
How do I convert GPS coordinates to a different format?
For the three degree formats, it is arithmetic: the whole number stays as degrees, the decimal times 60 gives minutes, and that decimal times 60 again gives seconds. Carry the sign or the N/S/E/W letter through every step. MGRS comes from a projected grid, so it has no by-hand shortcut and needs a tool or an app that reads it.
What are the four GPS coordinate formats?
Decimal degrees (DD), degrees and decimal minutes (DDM), degrees-minutes-seconds (DMS), and the MGRS military grid. The first three are latitude and longitude written three ways; MGRS is a separate grid system built on UTM. All four can describe the exact same point.
How do I convert decimal degrees to degrees minutes seconds?
Keep the whole number as the degrees. Multiply the decimal part by 60 to get the minutes. Then multiply the decimal part of that result by 60 to get the seconds. For example 38.8977 becomes 38 degrees, 53.86 minutes, which is 38 degrees 53 minutes 52 seconds. The direction stays the same throughout.
Can I convert MGRS to latitude and longitude?
Yes, but not by hand. MGRS is built on the projected UTM grid, so converting it to or from latitude and longitude needs a tool or an app that understands the grid. An app that shows your position in MGRS and in latitude and longitude at the same time skips the conversion entirely.
What coordinate format does Google Maps use?
Google Maps and Apple Maps both use and accept decimal degrees, like 38.8977, -77.0365. Paste a decimal-degrees pair into the search bar and the pin drops on it. If you have coordinates in another format, convert them to decimal degrees first.
How do I get my own coordinates in every format at once?
Use a location app that reads your GPS and shows all four formats together. LOC8 displays your spot in decimal degrees, decimal minutes, degrees-minutes-seconds, and MGRS, and lets you switch with a tap, so you never have to convert your own position by hand.
