financial requirement

The formula is:

16,000 + 2.5 (the shortfall) = amount needed.

If you earn 14,400 per year (based on 1200 per month), you're 4,200 short. That means you need 2.5 that amount, plus 16,000, which equals 26,500.

Thanks and how long does that need to have been in the bank ??

The full amount has to be in the bank for six months.

Can someone please advise me on which category I need to apply for a spouse visa I will be conbining my earnings from two employers which is £14,400 and savings of £26,500?

Also how long do I need to have worked with the two employers before I can apply?

Thanks

It's either Category A + D or B + D.
D is for savings.
B is usually the safer bet but requires up to a year's employment record, provided the combined income actually received from both jobs come to £14,400 (in your case).
You may be able to apply under Cat A if you have held both jobs for 6 months, though this is a grey area as the guidance doesn't explicitly state you can apply with two (or more) jobs, but doesn't say you can't.