# 95% confidence interval using confint()

If I'm being asked for a CI of 95%, how do I calculate a 95% confidence interval when R output gives the values for 2.5% and 97.5%?

Do I need to subtract the two values in order to obtain the 95% CI?
Or do I need to include something like ci = 0.95 for a 95% and not a 2 and 97%

`confint` does give you a 95% confidence interval by default.

Check out the docstring for `confint`. By default, the `level` parameter is set to a 95% confidence interval. A confidence interval is just that; an interval. By definition, intervals have two end points, and with the default endpoints, that means that your true parameter estimate will fall inside the interval given by `confint` 95% of the time. Check out this link for a more fully fleshed out explanation.

1 Like

That is a 95% interval - the 95% interval is the area between the points in the distribution. Note that `97.5-2.5=95`

2 Likes

This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.

If you have a query related to it or one of the replies, start a new topic and refer back with a link.