It definitely depends a lot on metabolic adaption which already varies significantly person to person but I think for beginners just moving from a sedentary lif

It definitely depends a lot on metabolic adaption which already varies significantly person to person but I think for beginners just moving from a sedentary lifestyle it's a good estimate for a while (six months to a year is the number I've heard, depending on training intensity). The last few months I've gone from a sedentary lifestyle to calorie counting and using an Apple Watch to track exercise with an intense 7-10 mile walk/run/hike 5-7x a week. With the weightloss I've experienced it seems relatively accurate (within 20%) but that's with 2-3 hours of exercise (not including weight lifting) per session.