Letâs look at a hypothetical spontaneous chemical reaction: The quantity of usable energy (chemical potential) in a reaction is called the Gibbs Free Energy (DG). DG is the difference between the energy contained in the products of a reaction and the reactants: DG = (energy of products) - (energy of reactants)
That's why some financial experts feel it's more realistic to think in terms of your net income, aka take-home pay, and that you shouldn't use any more than 25% of your take-home on your mortgage payment.
A $90,700 mortgage at 5.3% and you voluntarily paying $1,604 a month in principal and interest would pay off in 66 months. It is difficult to be exact because the numbers you provided are not exact, or, at least a little confusing. If you started at $150,000 mortgage balance for 15 years at 5.3%, the monthly required principal and interest payment would be $1,209.76.