I need to work out the amount of settlement discount taken by a customer:

I have the payment amount and the percentage.

How do I calculate the original invoice amount?

Here is what I have:

Payment amount: 6113.25
Percentage discount: 2.5%

I have used the goal seek function to work out that the original invoice amount is 6270.00

Can someone please help me to create a formula for this?
I need to calculate a lot of these and the goal seek option is very time consuming.

Thank you!

OriginalAmount * (1-(PercentDiscount)/100) = PaymentAmount

or

OriginalAmount = PaymentAmount / (1-PercentDiscount/100)

The easiest way I can think of is to simply divide $6113.25 by 0.975 to get the original balance of $ 6270(rounded up).

The .975 is the difference between 100% minus 2.5 %.

Since the amount $6113.35 represents 97.5% of the total balance.

OriginalAmount = PaymentAmount / (1-PercentDiscount/100)

This one worked! Thank you very much!