ToolPony.comDocumentation

Mortgage calculator

Compare a fixed-rate mortgage with down payment, recurring costs, extra payments, and biweekly payoff.

Get started

  1. Use the example values or enter your own measurements.
  2. Calculate, then copy the result or download the available details.

Example

Input

Home 400,000; down 20%; 30 years; 6%

Expected result

≈1,918.56 monthly principal and interest

Try it

Good to know

The calculation runs in your browser. Use consistent units in fields with no explicit unit.

Calculation method

Monthly interest equals remaining principal times the annual rate divided by 12. Costs follow your annual inputs and growth rates. PMI can stop at 80% of the original home value in this model. Biweekly compares half of the scheduled monthly payment every two weeks with interest divided by 26.

Ik=rBk−1,Bk=Bk−1−(Mk−Ik)I_k=r B_{k-1},\qquad B_k=B_{k-1}-(M_k-I_k)