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Learning, Sharing, and Teaching => Real Estate and Landlording => Topic started by: AlienRobotAnthropologist on May 05, 2017, 03:03:11 PM

I understand that with a mortgage, the early payments are mostly against the loan's interest, while the later payments are progressively against more of the principle. For a given mortgage, how do you calculate the amount of a given payment that will be applied to the interest vs the principle?

The concept you're describing is the Amortization Schedule. There are a bunch of calculators online (example: https://financialcalculators.com/amortizationschedule), or, with that search term, you can dig into the math behind calculating it.

http://www.myamortizationchart.com/articles/howisanamortizationschedulecalculated/

In google sheets, the formula to use is ppmt for principle and ipmt for interest. You can make up your own amortization table like this. I assume the formulas are similar in excel

http://www.myamortizationchart.com/articles/howisanamortizationschedulecalculated/
+1
And for the derivation, see one of amortization derivation  Google Search (https://www.google.com/search?q=amortization+derivation&ie=utf8&oe=utf8).