Frequently Asked Questions

The OpenMapChest maps work with the following Garmin devices:

• Nuvi series
• Zumo series - including derivatives such as the BMW devices
• eTrex, Oregon, Dakota, Colorado, Montana, Colorado and GPSMAP 62 handhelds
• StreetPilot if the device has an SD Card slot
• There are reports of these maps working on Kenwood in-car map systems (e.g. DNX521DAB) but the update procedure is a bit involved. This forum post should point you in the right direction but I'm not able to provide support for this.

Other Garmin devices with an SD Card slot should work but I haven't tested them personally. Let me know if the maps work on a device not listed here.

Hi 👋, I'm Ben Konrath.

I run OpenMapChest as a hobby. I love maps and created OpenMapChest to share the maps I make with other people. I hope you find them useful.

I spend my time on this project improving the maps and the map-making process, helping users who encounter problems, and improving the OpenMapChest website.

The maps are created using map data provided by the OpenStreetMap project, a user-editable map of the world. Extra address data is added for some maps from OpenAddresses (Canada, USA, Australia/NZ) and the United States Census Bureau TIGER dataset (USA).

Like all maps, the maps from OpenMapChest will have some errors. The advantage of using an OpenStreetMap based map is that you can fix any problems you find directly in OpenStreetMap and be using your fixes within a week. That's not possible with Garmin's official maps.

Want to make a change to the map data? Check out the OpenStreetMap beginners' guide to get started.

Most of the maps on this site are updated weekly so that everyone can benefit from the fixes and updates in the OpenStreetMap data without too much delay. The full Europe and full United States maps are updated on a bi-weekly basis.

The map build script is usually started Friday night / Saturday morning and takes about 4 days to complete - yes, it's a lot of data to process! You can expect an updated version of your favorite map to appear on the site sometime between Saturday and Tuesday.

The maps are created using the mkgmap map compiler. You can create your own maps by following the mkgmap map creation guide.

You sure can! 🚀

Instructions and the custom style file can be found in the OpenMapChest map build guide.

I kindly ask you do not label any maps you make as coming from OpenMapChest as this name is reserved for the official maps of this site.

Extra address data is added for the Canada, US maps from OpenAddresses and the United States Census Bureau TIGER dataset (US maps only).

The OpenAddress data is updated every few months and the Census Bureau TIGER data is updated annually shortly after it's released in the fall.

You can find information about the specific datasets we use on our Address Data Attribution page.

The maps on this site use the older Garmin format, the so called legacy or non-NT format. The maps work well and are very usable, but some features that were added to the newer NT format are not available, notably:

• No displayed speed limits: Speed limits are not displayed on screen while driving, however, speed limits are used for calculating the best route.
• No Junction View (JCV): These maps do not include Junction View images which means images of major highways, exits, and merge lanes do not appear while driving.
• No Lane Assist: These maps do not include Lane Assist which means icons of the lanes and which lane to use does not appear in the upper left corner when approaching a turn.
• Larger maps: The legacy (non-NT) format is less efficient than the newer NT format which means these maps are larger than Garmin's official maps.

We recommend that your fully restart your Garmin device after updating to a new version of the map. This ensures that the device will properly read the new map without having any of the previous map data saved in its memory. The OpenMapChest map should remain enabled when the device restarts.

How do you do this? Press on the power button for 4 seconds and you will be prompted to turn off your device. Once it's off, just press the power button again to turn it on.