What is the difference between 打算 (dǎ suàn) and 计划 (jì huà) Are 打算 (dǎ suàn) and 计划 (jì huà) both synonyms for "plan," or are there some additional nuances here?
打算 means 'intend to'(v) ; 'intention'(n) .  


Edit:

'打算' can mean 'to plan' (e.g. 为将来打算) or 'intend to' (e.g. 打算将来去英国) in English 

A '打算' can be an 'intention' or a 'plan'


  计划 means 'to plan' (v) ; 'plan' (n). 


When you 计划 (plan) something, you are formulating a workable plan with at least some form of mental calculations, and the objective should be a specific one. For example, 政府計劃[十年內逐步削減赤字, 達到收支平衡]. Which is a very specific objective

A '计划' is a 'plan'