Calculate a $5000 extra payment every 12 months that would be applied to the principle. Here is the current MS Excel spreadsheet info. I thought I would need an column for the $5000 extra payment so I created it.

 

Extra Payment Payment Beginning Scheduled Annual Number Balance Payment $5000Baloon Payment Date $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 $1,064.84 1 2 3 4 5 6 7 8 9 10 11 12 5/1/2022 $170,000.00 6/1/2022 $169,194.78 7/1/2022 $168,387.85 8/1/2022 $167,579.22 9/1/2022 $166,768.87 10/1/2022 $165,956.82 11/1/2022 $165,143.04 12/1/2022 $164,327.54 1/1/2023 $163,510.32 2/1/2023 $162,691.37 3/1/2023 $161,870.69 4/1/2023 $161,048.27 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 $100.00 Total Payment $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 $1,164.84 Principal $805.22 $806.93 $808.63 $810.34 $812.06 $813.78 $815.50 $817.22 $818.95 $820.68 $822.42 $824.16 Interest $359.62 $169,194.78 $357.91 $168,387.85 $356.21 $167,579.22 $354.49 $166,768.87 $352.78 $165,956.82 $351.06 $165,143.04 $349.34 $164,327.54 $347.62 $163,510.32 $345.89 $162,691.37 $344.15 $161,870.69 $161,048.27 $160,224.11 $342.42 $340.68 Ending Balance This is the scheduled payment formula=IF([@[Payment Number]] "",Scheduled Payment,"") This is the extra payment formula=IF([@[Payment Number]] "",IF([@[Scheduled Payment]]+ExtraPayments