如何计算 Excel 中具有可变还款额的抵押贷款的加权平均寿命

How to calculate the weighted average life for a mortgage in Excel with variable payment

我想弄清楚如何使用以下利率为 7% 的抵押贷款的现金流量计算截至 2016 年 6 月 30 日的现值和加权平均寿命。

对于 WAL,我尝试了利息支付/利率 x 原则,但没有用。如果有任何想法,我将不胜感激。

Dates        Principal      Interest   Ending Balance
15-Apr-16    $-             $-           ,000,000 
15-May-16    ,000         ,667     ,950,000 
15-Jun-16    ,000         ,840     ,900,000 
15-Jul-16    ,000         ,250     ,850,000 
15-Aug-16    ,000         ,410     ,800,000 
15-Sep-16    ,000         ,194     ,750,000 
15-Oct-16    ,000         ,625     ,700,000 
15-Nov-16    ,000         ,764     ,650,000 
15-Dec-16    ,000         ,208     ,600,000 
15-Jan-17    ,000         ,333     ,550,000 
15-Feb-17    ,000         ,118     ,500,000 
15-Mar-17    ,000         ,944     ,450,000 
15-Apr-17    ,000         ,688     ,400,000 
15-May-17    ,000         ,167     ,350,000 
15-Jun-17    ,000         ,257     ,300,000 
15-Jul-17    ,000         ,750     ,250,000 
15-Aug-17    ,000         ,826     ,200,000 
15-Sep-17    ,000         ,611     ,150,000 
15-Oct-17    ,000         ,125     ,100,000 
15-Nov-17    ,000         ,181     ,050,000 
15-Dec-17    ,000         ,708     ,000,000 
15-Jan-18    ,000         ,750     ,950,000 
15-Feb-18    ,000         ,535     ,900,000 
15-Mar-18    ,000         ,611     ,850,000 
15-Apr-18    ,000         ,104     ,800,000 
15-May-18    ,000         ,667     ,750,000 
15-Jun-18    ,000         ,674     ,700,000 
15-Jul-18    ,000         ,250     ,650,000 
15-Aug-18    ,000         ,243     ,600,000 
15-Sep-18    ,000         ,028     ,550,000 
15-Oct-18    ,000         ,625     ,500,000 
15-Nov-18    ,000         ,597     ,450,000 
15-Dec-18    ,000         ,208     ,400,000 
15-Jan-19    ,000,000      ,167     ,400,000 
15-Feb-19    ,250,000      ,861     ,150,000 
15-Mar-19    ,250,000      ,917     ,900,000 
15-Apr-19    0,000        ,097     ,500,000 
15-May-19    ,000,000      ,750     ,500,000 
15-Jun-19    ,500,000      ,764     $- 

  1. 截取 2016/6/30 之前的日期,保留大于或等于 2016/6/30 的日期。 (如上)。
  2. 创建CF列,=C3+D3
  3. 创建no_of_years列,=(B3-$B)/365
  4. 创建CF*no_of_years列,=G3*F3
  5. 使用XNPV函数得到现值,=XNPV(0.07, F3:F39, B3:B39)
  6. 通过 =SUM(H3:H39)/SUM(F3:F39)
  7. 获得 WAL