Duolingo goals: German, French, Spanish
So My original goal for my three languages was to do 20xp a day for each language but Im actually on average doing 100xp a day for each language. At this rate, how long should it take for me to finish the German, Spanish and French duo lingo courses?
XP's are related to the time you spend, not with how well you master the language. You can keep strengthening the first lesson until you have 3400xp, or you can finish the tree without gathering so many xp's. If your goal is to finish the trees, don't strengthen and don't repeat. If your goal is to learn a language, then you strengthen and repeat, take twice as long to finish the tree, but at least you'll have learned something.
I just finished the French course for review and it seems to be around 3500+ XP, so that'll take you a about five weeks to complete if you keep up with 100 XP a day barring any practice / repetition. I think you could finish in under two months.
Finished the Spanish tree, nearly done with French and just started German. Depending on how you'd approach it, I would say 6-10 months.
I took 13,500 to finish French, that would equate to 135 days at your speed.
I have been building my trees a little faster. Have finished the German tree and will finish both the French and the Spanish trees in about a month. By then, I will have spent five months. I think, You will be there in about six months.
In Duo's first year it took less than 3 months to finish French at level 14 (IIRC) doing at least 100 XPs per day. My guess is that it would be about the same now. Anything since then I haven't paid attention to, as my practice involved more than one language each day.
It seems to me now, however, that it is better to finish a course w/ a higher level than the average (which is 12-14, I think), so it would take longer to finish or would need more XPs per day.
You could try two at once like Spanish and German. So Duolingo + Lingvist every day for both.
Then once you finish the Spanish tree and hit A2 try "laddering" aka the Spanish->French tree.
Just my 2 cents so you don't become burnt out/confused.