'-을 만하다' is a way to say that something is worth doing. It's used for recommending to a listener but are probably not wildly excited about it. It's worth the time, but not more than that.
그 영화는 한 번쯤 볼 만해요. That movie is worth seeing once.
인생은 살아 볼 만해요. Life is worth living.
믿을 만한 여자니까 뭐든지 얘기하세요. She is trustworthy so you can tell her anything.
그 여자의 용감한 행동은 칭찬할 만해요. That woman's brave deeds are worth praising.
새로 나온 그 책은 읽을 만해요. That new book is worth reading.
그 콘서트에 나오는 밴드가 다 좋아서 정시에 맞춰 갈 만해요. All the bands at that concert are good, so it's workth arriving on time.
'-을 만하다' is also used to indicate that it is till worth doing or paying attention to, while the speaker is not completely satisfied with it.
재활용 센터에 가면 아직 쓸 만한 중고 가전제품이 많이 있습니다. There are many sericeable used appliances in the recycling center.
이 옷은 10년 전에 산 옷인데 아직도 입을 만해서 안 버렸어요. I bought these clothes 10 years ago, but I didn't throw them out because they're still worth wearing.
며칠 전에 만든 음식인데 아직은 먹을 만한 것 같아요. This food was made a few days ago, but i still seems edible.
2. to be obvious; to have high possibilities, to deserve
지금쯤이면 회의가 끝났을 만해요. The meeting shoub be over by now.
열심히 했지만 결과가 안 좋으면 화가 날 만해요. She/he deserve to be angry when the results are not good after hard work.
일이 그렇게 많으면 힘들 만하죠. It's obviously tough for him/her having such amount of work.
있을 만하지도 않은 일로 걱정하지 마. Don't worry with something that is not even likely happen.
<참고> Jaehoon Yeon and Lucien Brown(2011), Korean: A comprehensive Grammar, 402. Laura Kingdon(2015), Essential Korean Grammar, Tuttle, 49, 333. 강현화 외(2016), 한국어교육 문법 자료편, 한글파크, 586-587. Min Jin-young & Ahn Jean-myung(2021), Korean Grammar in Use Intermediate, 132-133.