at least

(さいしょう) A minimum amount of something:daily minimum of calcium in your diet. This factory strives to operate with a minimum of toxic waste. This is more scientific and less moral than すくなくとも or 最低.   TTT
すくなくとも At least xxx:more used about actions than amounts of things, and often with a ‘you should’ feeling:  You should (study at least 4 minutes every day) (go on at least 3 job interviews a week), etc.   $$$
(さいてい) Basically the same as すくなくとも.
せめて Kind of different from the rest. せめて has no English equivalent. It kind of means ‘at least’ in the metaphorical sense:“He got dumped by the model, and lost his job at UPS, but at least he has more free time now.” “If you’re going to bring over all your ex-con friends to the party, at least you could warn me ahead of time.”