The uploaded image dimensions affect sharpness, but they don't control how large the marker appears on the map. StoreRocket uses the Pin size selected for your project.
How do I change how large the marker appears?
Choose Very small, Small, Medium, Large, or Very large
Select Save and check the live store locator
The preview beside the settings shows the new size as you pick it. This setting applies to every custom marker in the project. Uploading a larger source file won't make the displayed marker larger.
You can also change the size from Settings at the top of the Map Markers page. That menu calls the smallest and largest sizes Extra small and Extra large. They are the same two sizes.
What is the recommended image setup?
Use a PNG with a transparent background or an SVG
Keep the file under 1MB
Use a square canvas
Make the artwork fill most of the canvas
Keep the design simple enough to recognize on a map
Large transparent margins make the visible artwork look smaller. Keep only enough space to prevent the design from touching the edge.
For uploading, assigning, and setting default markers, see Custom Map Markers: Upload, Sizing, and Assignment.