Free mortgage schedule tool
How much principal and interest will I pay each month?
Mortgage Amortization Schedule
A mortgage amortization schedule shows how each payment is divided between interest and principal, how the balance declines, and how additional principal changes the payoff. Enter the mortgage terms below to create monthly and annual schedules, estimate cumulative interest, and export the results as a CSV file.
- Free to use
- No account or email required
- Calculates in your browser
- Editable assumptions
How to use: Replace the example values with the scenario you want to explore. Results update as you type. Open the detailed sections for assumptions, breakdowns, and schedules.
Privacy: Rich Direction does not connect calculator entries to an email address, contact record, advertising audience, or analytics event.
What this tool calculates
What will the calculator show?
- Builds a complete month-by-month amortization schedule.
- Summarizes principal, interest, extra principal, remaining balance, and total housing outflow by year.
- Shows cumulative interest and principal after every payment.
- Models recurring and one-time additional principal.
- Exports the displayed schedule locally as CSV.
Who this tool is for
When is this calculation useful?
This tool is for borrowers who want a detailed repayment schedule, want to verify the direction of principal reduction, or want to compare additional-payment strategies.
Not designed for: It is not an official lender statement or payoff quote and may not match loans that use daily interest, adjustable rates, changing escrow amounts, fees, or irregular payment timing.
Input guide
What do the inputs mean?
- Mortgage principal
- The starting loan balance to amortize.
- Annual rate and term
- The fixed rate and number of monthly payments.
- Start date
- The date used to label projected payment months.
- Recurring extra principal
- An optional amount added to each modeled payment.
- One-time extra principal
- An optional lump sum and the payment month in which it is applied.
- Taxes, insurance, PMI, and HOA
- Recurring costs included in total outflow but not in principal amortization.
Results guide
What do the results mean?
- Monthly schedule
- Beginning balance, payment, interest, principal, additional principal, and ending balance for each month.
- Annual summary
- Yearly totals for principal, interest, extra principal, ending balance, and housing outflow.
- Cumulative totals
- Interest and principal paid through each selected payment.
- Estimated payoff
- The projected final payment date under the selected extra-payment assumptions.
Calculation methodology
How does the calculation work?
For each month, interest is calculated from the beginning balance and monthly rate. The remaining scheduled payment reduces principal, followed by any additional principal. The next month begins with the reduced balance. The final payment is shortened when necessary.
Model assumptions
- The rate remains fixed for the full schedule.
- Payments are made monthly and on time.
- The lender applies additional amounts directly to principal.
- Escrow and association costs remain at the entered amounts for total-outflow reporting.
Worked example
How should I interpret a result?
A borrower can enter the current principal, rate, remaining term, and an additional $100 monthly principal payment. The schedule then shows the revised balance after every payment and compares the accelerated payoff timing with the modeled term.
Important: The example explains the method. Your result depends entirely on the assumptions you enter.
Decision guidance
What should I compare next?
- Compare selected rows with your lender statement to identify differences in timing or servicing method.
- Ask the servicer how to designate additional principal and whether any restrictions apply.
- Export the schedule and preserve the assumptions used for the comparison.
Important limitations
What can change the actual result?
The schedule assumes the entered rate, payment timing, and additional principal remain consistent. Actual lender statements may differ because of daily interest, escrow changes, fees, payment dates, or servicing practices.
Use the calculator as an educational comparison tool and confirm material figures with source documents, providers, lenders, taxing authorities, or qualified professionals as appropriate.
Sources and verification
Where can I verify the broader financial concepts?
External sources provide general consumer information. They do not validate a specific calculator result or endorse Rich Direction.
Authorship and maintenance
Who prepared this page?
Prepared and reviewed by Rich Direction, LLC. Calculator methodology and explanatory content last reviewed July 27, 2026.
Report a possible error or outdated assumption to support@richdirection.com.