Mortgage Calculator

Calculation formula of equal principal repayment :

1. Monthly contributions =( Loan principal ÷ Number of repayment months )+( Loan principal - The accumulated amount of principal paid back )× An interest
2. Monthly repayment of principal = Loan principal ÷ Number of repayment months
3. Monthly interest payable = Remaining principal × An interest =( Loan principal - The accumulated amount of principal paid back )× An interest
4. Decreasing amount of monthly supply = Monthly repayment of principal × An interest = Loan principal ÷ Number of repayment months × An interest
5. Total interest =〔( Total loan amount ÷ Number of repayment months + Total loan amount × An interest )+ Total loan amount ÷ Number of repayment months ×(1+ An interest )〕÷2× Number of repayment months - Total loan amount

B Equal principal and interest monthly payment
A The total amount of the loan
i  An interest

n Loan period （ Unit month ）
An interest = Annual interest rate /12

Equal principal

  //  Equal principal   Total interest 
  getMonthMoney5(a, n, m) {
        // 5. Total interest  =〔( Total loan amount ÷ Number of repayment months  +  Total loan amount × An interest ) +  Total loan amount ÷ Number of repayment months ×(1 +  An interest ) 〕÷2× Number of repayment months  -  Total loan amount 
    // a  The principal 
    // n  Total repayment months 
    // t  Current repayment months 
    // m  An interest 
    // lx  Total payment 
    var lx = 0
    for (let t = 1; t <= n; t++) {
      lx =  (a - a * (t - 1) / n) * m
      lx = lx + lx
    }
    console.log('lx>>', lx)
    return lx

  },