Which sentence is better between “I’m OK.” and “That’s OK.”

Question

I'd like to know the simple expressions without offending others when I'm offered some help by friends, acquaintances or stangers. This is one example. Someone offers me help when I'm carrying a bag saying " Can I help you with your bag?" Another example is when I'm doing the preparation for the party, someone says " Do you need any help?" When I think I can manage, what sentence can I use? There seem to be several possible phrases as follows. Could you tell me the difference of these phrases?

1. Thank you, but I’m good.
2. Thank you, but I’m OK.
3. Thank you, but I’m fine.
4. Thank you, but that’s OK.

Answer 1

I would say

I'm OK, thanks.

That puts the fact that I am OK as I am (no help is needed), and then thanks.
OK is simple to understand; there is no problem.

And I prefer a simple thanks; I think thank you is too formal replying to a stranger who speaks to you first. Especially if someone was bothering you (asking if you needed help when it was obviously not necessary).

Answer 2

The answer may depend on where you are, geographically-speaking. I'd like to provide an illustrative example, below.

Having spent a great deal of time in Montreal, QC, and Baltimore, MD, I notice a difference in this particular phrase. I might recommend that your #1 answer (Thank you, but I'm good) would be heard more often in Maryland, while your #2 answer (Thank you, but I'm okay) would be heard more often said to a friend in Ontario or Quebec. Even then, your #3 answer (Thank you, but I'm fine) would be heard more often when spoken to a person in a position of authority or a stranger in both locations.

Why did I italicise the more often? Simply because I think that all of these answers are acceptable.

Answer 3

Assuming that you're being offered help by a stranger in an airport or a bus or train station, and that you don't want your bag stolen, and don't want to encourage any additional conversation, I'd say Thank you for the offer, but it's not a problem if you have enough breath and don't want to be too dismissive, or Thank you, I'm fine if you want to be brief. The other three just don't sound right to me, but others may disagree.

Answer 4

If a friend offered help, then I’d probably say

Thanks much for the offer, but I think I can manage.

Answer 5

The four examples you listed are not offensive ways to reject assistance. They could be taken offensively depending on the tone of your voice and body language (by acting snobby or conceited). I would say:

Thanks, but I'll be ok. (Thank you, but I will be ok.)

A blatently offensive way of rejecting assistance would look like this:

No! Why would I need your help?