Promising big and delivering small is worse than promising nothing. The gap is what people remember.

People do not measure your work against zero, they measure it against whatever you told them to expect. A decent result after an enormous promise reads as failure, while the same result offered quietly would have been a pleasant surprise. The gap is what gets judged, and you are the one who set the number in the first place.

Say the lower figure out loud and keep the extra to yourself. Promise Thursday and deliver Tuesday. Same work, completely different reputation by the end of the year.