How accurate are FastPass estimates

Im wondering how accurate the fast pass times are in touring plan. Recently i’ve noticed that touring plan estimates for wait times etc is about 5 min out for each ride. Over 10 rides thats an hour. How accurate from past experience are these FP return times. I’m worried if the times are totally out it throws out the entire day / plan.

Havent done DL but when WDW had old style fpp return times were pretty accurate wait times might have been out by 5/ 10 minutes for SB but fp wait times were pretty close. The tp is only a guide you cant account for every minute and they are only estimates. A ride breaking down will throw your plan out kids having a melt down will throw your plan out as will not having enough potty breaks in the plan or allowing enough breaks for drinks and food and kids spending 5 minutes looking in the shops or buying a souviner. All of these will thow you plans out more than waiting an extra 5 mins in a queue Allow an extra 15 minutes break every 2 hours to catch up is highly recommended and at least 60/90 minutes for each meal