2 Replies Latest reply on Dec 15, 2011 1:24 AM by mendico

# Calculation

Can anyone help me. I am a first time user of Filemaker. I have a business and need to create a new invoice.

The invoice I have created starts with an invoice total which then I need to calculate the various percentage amounts for each field as show in the table below eg: 20% by the due date, giving me a balance owing until all fields are completed. Not sure if I have explained this properly. Please advise me. Thanks.

• ###### 1. Re: Calculation

mendico wrote:

Can anyone help me.  I am a first time user of Filemaker.  I have a business and need to create a new invoice.The invoice I have created starts with an invoice total which then I need to calculate the various percentage amounts for each field as show in the table below  eg: 20% by the due date, giving me a balance owing until all fields are completed. Not sure if I have explained this properly.  Please advise me.  Thanks.

Hello mendico,

The calculations you need are relatively straightforward. You need to set up each of the fields using the Calculation field type, select a result type of number and enter a formula for each. For the Deposit and the 2nd and 3rd instalments, you will be able to enter the calculation formula:

Round(Invoice Total * 0.2; 2)

For the Final Payment amount, I'd suggest you use a formula along the lines of:

Invoice Total - 3 * Round(InvoiceTotal * 0.2; 2)

This is better than simply multiplying the invoice total by 0.4 for the final payment amount, as it will resolve any rounding errors introduced in the earlier calculations.

Meanwhile, assuming you're recording the actual amounts paid somewhere, it should be possible to also calculate the Balance Owing amount by sinply subtracting each of the amounts paid from the Invoice Total - or, if they are in a related payments table, by subtracting the sum of related payments from the Invoice Total. The formula for this would be along the lines of:

Invoice Total - Sum(Payments::Amount)

...however the exact construction will depend on how you're recording the payment amounts and (of course) on your field and table occurrence naming.

Regards,

Ray

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R J Cologon, Ph.D.

FileMaker Certified Developer

Author, FileMaker Pro 10 Bible

NightWing Enterprises, Melbourne, Australia

http://www.nightwingenterprises.com

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• ###### 2. Re: Calculation

Hi Ray,

Your advise was greatly appreciated. I have now put it into place and am very excited about distributing my new invoice to my

up coming clients.   It will make life so much easier.  Again, thanks.  Regards, Tony Mendico