Nick here from Shopify. Great question!
@janigorse is correct here. You can indeed embed this feature into a page on your website. Once on the page, you want to edit in the admin, you would need to click the icon with the two arrows which looks like this <> below the title.
I did see on the link which Jani shared there was a warning in red that the map feature might not be available in the near future. It could be worth reaching out to a Shopify Expert to see if they can help create another code for this, so you would not be reliant on this feature specifically. I had a good look through the app store and didn't find any apps with a Google map calculator feature. Perhaps creating your own one with an Expert could be the most reliable direction to take. At the moment, the only aspect of Google Maps which is commonly added to stores is the feature to show where your store is located which you might need to take to the next level.
Hope this helps!
All the best, Nick