After Tax Mortgage with Extra Payments Calculator

How to use the after tax mortgage with extra payments calculator

1. Prepare the values for this calculation

   Model mortgage payoff with an optional extra payment each payment period. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.

2. Enter and check each input

   • Home price: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Down payment (%): enter a value at least 0 and no more than 99.9. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Annual nominal interest rate (%): enter a value at least 0 and no more than 100. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Term (years): enter a value at least 0.01 and no more than 50. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Annual property tax (% of value): enter a value at least 0 and no more than 20. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Annual homeowners insurance: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Monthly HOA/other housing charge: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Upfront/financed fees: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Extra payment per payment period: enter a value at least 0. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Inflation assumption (%): enter a value at least -99 and no more than 100. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Marginal tax-rate assumption (%): enter a value at least 0 and no more than 100. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Interest treated as deductible in this model (%): enter a value at least 0 and no more than 100. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Early-payoff penalty assumption (%): enter a value at least 0 and no more than 100. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Points paid (% of loan): enter a value at least 0 and no more than 20. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Modeled rate reduction per point (percentage points): enter a value at least 0 and no more than 10. Use the unit named in the label or selected above. Do not leave this required field blank.
   • Elapsed years before payoff/penalty: enter a value at least 0 and no more than 50. Use the unit named in the label or selected above. Do not leave this required field blank.

   The input table gives a complete example. Keep units and time periods consistent across related fields.

3. Calculate and resolve any input error

   Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.

4. Interpret the answer

   Check Mortgage result first. With the unchanged example inputs, it is 361 payments. Compare the additional metrics with the primary result; each has its own label and unit.

5. Compare and keep a useful result

   For a controlled comparison, keep every other example input unchanged and change Home price from 400000 to 440000. The resulting Mortgage result is 360 payments. This illustrates the equation’s response to that input, rather than a forecast of real events.

   Read the chart’s axis labels and data table. A scenario curve changes one stated input while holding the others fixed; it does not add external observations. Use Download graph to save an available chart as a PNG.

   Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.

After Tax Mortgage with Extra Payments Calculator formula

The required payment is calculated from the fixed-rate formula, then the balance is iterated period by period with extra principal until payoff.

Inputs and units

Worked example

Using the example inputs above, the mortgage result is 361 payments.

Mortgage result

361 payments

Scheduled payment

$2,022.62

Extra per payment

$0.00

Modeled interest paid

$408,142.36

Payments saved

0

Approx. interest saved

$0.00

Results and assumptions

The output uses the mortgage result convention and formula shown above. Match the entered units and source assumptions when comparing results.

Rates, fees and tax assumptions are entered values. This calculation does not quote a lender, determine a tax liability or guarantee an investment return.

Fix an input or unexpected result

Home price is required. Enter home price using the format and bounds in the input table. Zero and an empty field are different: use zero only if it is allowed and represents your data.

If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.

If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.

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