Function for fixed amounts spread over 12 payments

[Guest]

I need a functions that will change the remaining payments when the original
amount is either increased or decreased.

We have contracts that are paid in 12 equal payments each month, but when
the amount is either increased or decreased, I need the remaining payments to
reflect the change. Does any one know a formula that will work for this?
Thanks.

 

[Guest]

=(New Contract amount - payments-to-date)/number-of-payments-remaining

As you didn't give any info on how your data is organised, I can only
generalise as above.

You may need to adjust payments (last one?) if the outstanding balance does
not divide exactly by the number of payments remaining.

 

[Guest]

Sorry, I did not give you enough information. This information will look
like this.

Original Contract 120,000
Increase/Decrease 9,000
Amended Contract 129,000
July Payment 10,000
Aug Payment 10,000
Sep Payment 10,000
Oct Payment 10,000
Nov Payment
Dec Paymnet
Jan Payment
Feb Payment
Mar Payment
Apr Payment
May Payment
Jun Payment
Total Payment 40,000
Balance of Contract 89,000
Remaining Payment Amount 11,120

What I would like is the remaining payment amount to always show the next
payment amount.

 

[Fred Smith]

OK. Given this additional information, what's wrong with Topper's formula? Why
won't it work for you?