How many borders does the united states have with canada?

13

Explanation:

There are 13 states that border Canada: Alaska, Michigan, Maine, Minnesota, Montana, New York, Washington, North Dakota, Ohio, Vermont, New Hampshire, Idaho, and Pennsylvania.

However, if you are asking only how many land borders and don't care about how many states, then the answer is more than 100.

Explanation:

The Canada-United States border is the longest international border in the World at 5,525 miles. There are more than 100 land border crossings between Canada and the USA, although not all of these are open 24 hours a day 7 days a week year round.

Hope this helps! :)