While there is no way to completely get around these limitations, we can use a method called map tiling to upload maps that are larger than these limits and view them in full resolution. It doesn't matter if you have the storage space, any more and they won't load. Depending on your device (details here), you can upload no more than 100 or 500 custom map images or tiles.All map image files must be less than 3 MB.In other words, fine map details and text will become indistinguishable.

in short, any image that contains more than 1048576 pixels) will be displayed at a reduced resolution on your GPS. Map images over 1 megapixel in size (1024x1024 pixels, 512x2048 pixels.To encourage us all to pay for their premium maps and services, Garmin has placed several limitations on the size and number of custom maps that can be uploaded to their GPS devices. You can download the originals or rely on my descriptions to get a sense of image quality. I believe this is due to compression used by the website when loading the images. Please note that many of the screenshots in this Instructable look pretty bad. In this Instructable, I'll lay out a simple process I've come up with for making custom maps for Garmin outdoor GPS units and share the entirely free tools I use to do it.

So many tools and suggestions, in fact, that it's a bit overwhelming. Of course, they won't tell you some clever tricks to get around them! While it's not possible to completely circumvent Garmin's limitations, there are a wealth of tools online - some free, and some not - that can help you make better custom maps. Garmin has purposefully included limitations on the size and number of custom maps you can upload to your device to encourage you to purchase their premium maps. Garmin provides instructions for doing this here, but there's a catch. Even if your unit came with TOPO maps, you can improve the functionality of your GPS by creating and uploading custom maps of areas you explore often. If you have a Garmin GPS designed for hiking and other outdoor activities (including the GPSMAP, eTrex, Colorado, Dakota, Oregon, and Montana series, among a few others), you don't have to settle for the bare-bones maps that came pre-loaded on it.

Garmin custom maps download