计划 nuon or adverbial modifier 打算 nuon or adverbial modifier 安排 verb or adverbial modifier 计划 plan 我有一个计划 have a plan 他们计划穿过太平洋 they planned to voyage across the Pacific Ocean 计划一般用于书面或正式场合 打算和计划是一个意思 但用于朋友之间聊天或非正式的场合 安排 你有什么安排？ what is your plan 我安排小李去上海 let xiaoli go to shanghai 我让小李去上海

计划：usually used in written language, especially in goverment report 打算：spoken language, we say: "打算看电影" but barely say：“计划看电影” 安排：”安排sth“， different from “打算do sth” eg. 安排你和Sam见面 打算和Sam见面

They are all very similar. It is important to point out though 打算和安排 is not used so often in formal/business context. To be precise, I would say 计划 is more high level planning and the other two are more tactical and operational.

计划：make a plan 打算：want to do 安排：to arrange

計畫 --> plan to 打算 --> intend to 安排 --> arrange st.