Make Calc recognise Formula pattern in cells via Autofill

[MartinMüsli]

HI there,

I am trying to get a compound interest table going.
In the top, i have written down my contract details with the yearly payrate and compound interest rate.
At the bottom I have a list of the following years. Next to it, I would like to Autofill the Formula which calculates the amount that I need to pay in that year.
The Table looks like this:

          H           I
16                  contract
17        payrate 	23.00 €
18        ci	    3.00%
19
20        2020	    23.69 €
21        2021	    24.40 €
22        2022	    25.13 €
23        2023	    25.89 €
24        2024	    26.66 €

The Formula for cell is I20: =I17+I17*I18. (This must be typos, imo. Please edit to rectify. - Lupp)
For cell I21 the formula is now based on the cell I20: =I20+I20*I18.
For cell I22 the foormula is again now based on the previous cell I21: =I21+I21*I18.

Once i mark the I20 and I21 cells and apply autofill (dragging the marked section down), the formula is messed up.
I would expect, that Libreoffice recognises, that the Cell I18 will stay constant in my formula. However Calc counts it up. So in the following Cells, the Cell I18, would be I19, I20, I21, etc.

How can I apply this simple formula to all the remaining cells without typing each one individually?

[Lupp]

The (single) asterisk is used by the editor here in pairs to markup text to be displayed italic. It can therefore not be used for the multiplication operator without “escaping” this special functionality. Use the tool ‘preformatted text’ for formulas and code.
(Pairs of double-asterisk are used to markup for bold.)
I slightly edited the question to get better readability.

[anon73440385]

Hello

if you want a cell reference stay constant - then you need to use absolute addressing using $. Therefore replace I18 by $I$18. See also LibreOffice Help - Addresses and References, Absolute and Relative

Hope that helps.

If the answer helped to solve your problem, please click the check mark () next to the answer.

[MartinMüsli]

It was as easy as that. Thanks