16/8 to 18/6 is my core IF these days, but frankly i've been all over the place recently. yesterday i went about 20/4 just because by the time i thought about eating dinner, it was way too late and i really wasn't that hungry. but a few days ago i know my day was more like 12/12. if i stick to this, only eating when i'm hungry (on my scale, probably not the same as most people), i really need to plan my days better. especially if i have food on hand (no prep... planned leftovers) i think i tend to eat too much at breakfast. i will try to cut back on that and see if i can more easily squeeze in a moderate dinner without that "OMG, i have to eat now before it's too late", stress.
shoot for that 18/6, but more importantly, draw the line at 14/10. if you hit that a day or two now and then, you'll still maintain that long term effect. that 12/12 day of mine was an anomaly.