You lose £4.35 of UC monthly for every £250 (or part thereof) for savings between £6k and £16k, so £9k of savings would give a deduction of £56.55 or £52.20, depending on whether it is just over or just under £9k.
Are you renting? If so, find out the local housing allowance for your area. Unless you have DCs (which you haven't mentioned), you'll only be entitled to the one-bedroomed rate.
The standard allowance for a couple is £594.04 a month. Add this to the LHA figure, this will give you your maximum entitlement.
Then, multiply your net pay by 0.63, and subtract this figure from the maximum entitlement. If you end up with a minus figure, you won't be entitled to anything. If it's a positive, that's what you'll get, less the £50-odd referred to above.
You'd have to be in a very high rent area to qualify for help as a child-free couple with an income of £1,800 pcm, but may if either of your jobs go tits up.
It gets more complicated if you have children, because part of your earnings will be disregarded, plus you get child elements added to your maximum entitlement.
And the advice about paying off debts to reduce your savings to below £6k is spot on. If you have various debts, pay the one with the highest interest rates.