If I normally shoot 85 on average from the middle tees, am I about a 13 handicap? Do I need to play from the tips for a true handicap, or are the slope ratings of each course used to calculate a true handicap?

Each tee box should be rated. Check the scorecard. If the tees you are using aren't rated for some reason then you'll have to use the other tees or ask the club if there is a rating for the tees you normally play.

The courses I play have a rating for each tee box.

No, you are probably not a 13. More than likely something less.

Keep in mind that a handicap is not meant to be an indication of your "average" score. It is meant to represent your potential to score when you are playing well.

For instance, you might average 85, but on "good rounds" you shoot 79 or 80. Then you'd be closer to a 7 or 8 handicap. You could shoot 110 when you play poorly, and it wouldn't matter, as handicaps are calculated only on your best scores.

Each time you enter a score, you also enter the course and tees. Each course and set of tees is rated differently. The only way to keep a handicap is to actually post your scores. If you don't post, you are only guessing, and you don't have a handicap.

thanks guys... know of any free handicap tracking web sites?

http://fairwayfiles.com/

As good as your going to get for free.

I prefer leaderboard.com

great software, free, with lots of stats if you care to use them.

I use these two...

http://www.mobilegolfstats.com/

http://golf.sports.yahoo.com/tracker

Actually, more than likely your handicap is higher than 13. This is because for most courses, the rating from the white tees is usually much less than par ... usually in the range of 65-68, 4 or 5 strokes less than par for average courses. Slope will have the most effect though, and tends to vary more widely between courses.

I took 3 courses from around here, the easiest I have played, the toughest I have played, and one I consider an average course around here, and used a score of 83, which is probably close to the average of your top 10/20 if you usually shoot near 85.

The results:

Easy course, 63.8/105, handicap of 19.8 (this course is really easy, far and away easier than any other around here)
Average course, 66.9/117, handicap of 14.8
Hard course, 68.1/122, handicap of 13.2

So it is unlikely your handicap is as low as 13, and could be closer to 20 depending on the courses you play. If you are playing average type courses, it is probably very close to 15.

Strange because here (unless you are playing muni courses) most course ratings are at par. Of the ones that are rate 71 or so have a pretty high slope rating.

Granted I suppose it depends on what yardage you play from.

Well, the average course around here (St. Louis) usually has 3 sets of tees marked, usually red, white, and blue. The back tees are usually rated pretty close to par (usually within a stroke). The middle tees (which the OP is playing from) usually 3-5 strokes under par. Many of these courses have a 4th set of tees on the scorecard (usually black) that are not usually marked, and used for tournaments. The nicer courses often have 5 tees, but still the tips aren't usually marked for every day use.

If your average score is 85, you are probably about a 9 handicap. Maybe less, maybe more. I've known 6 hcp golfers that average 85, but they have enough low scores to keep their handicap down.

I probably average about 78 and I'm a 3 handicap. By your guesstimation I'd be a 6.

Get into a handicap system online or through a local public course. Then there is no question.