Example 1
- Principal: 300,000
- Rate 6.5%, term 25 years
- Extra: +300/mo.
6 yr 5 mo. earlier
Interest −91,174.74
An extra 300 a month shortens a 25-year loan by more than 6 years and cuts interest by about 30%.
Amortization calculator
Type the loan principal, the annual interest rate, and the loan term in years. The calculator builds a full annuity schedule and compares it with extras. At 300,000, 6.5%, 25 years, and a recurring extra of 300 a month you finish 6 years and 5 months sooner, and interest falls by 91,174.74.
Full annuity table plus an extras case. Fixed rate, no prepayment fee. Quick sketch without the table: loan overpayment. A simplification, not a contract.
Result
Loan principal, Annual interest rate (%), Loan term (years) and First payment date (optional). The result shows up here.
Payment schedule
How results are calculated
The amortization schedule builds every annuity payment, the equal installment, from Loan principal, Annual interest rate (%), and Loan term (years). At 300,000, 6.5%, and 25 years plus Recurring monthly extra 300 you finish 6 years and 5 months sooner, and interest falls by 91,174.74 versus the no-extra case. At 400,000, 7%, 30 years, first payment date January 1, 2026, and Recurring yearly extra 6,000 in December, time saved is 10 years and 6 months and interest is down 222,094.77.
A one-time lump of 15,000 on payment 24, on 200,000 at 5.5% for 20 years, cuts 2 years and 3 months and 22,880.72 of interest. Extras go to principal. The calculator keeps a fixed rate: it does not reset an index mid-term and it does not add a prepayment fee. This is a teaching table, not a file from an offer.
Required fields are Loan principal, Annual interest rate (%), and Loan term (years). First payment date is optional and fills the date column. Options hold Recurring monthly extra, Recurring yearly extra, Month for the yearly extra, One-time lump sum, and Lump sum on payment #. You can set the extras case next to the base. A quick compare without 300 rows lives on loan overpayment.
Balance after N payments is one snapshot, not a table. Debt repayment times a horizon from a balance and a fixed payment. The loan installment page shows 1,112.22 alone, with no chart. This page is the full table. Header currency only labels the amounts. A comma and a period in 6.5 mean the same rate.
The calculator waits for a positive principal, rate, and term. This is a fixed-rate sketch, not a credit decision and not an amendment. An offer may round each payment differently and may add a fee that is not here.
Type 300,000, 6.5, 25, and 300, click Calculate, and check 6 years 5 months and 91,174.74. Then try 200,000, 5.5, 20, and a 15,000 lump on payment 24 to see 2 years 3 months and 22,880.72. The leftover line is Interest saved, not a new loan.
How to use
- Type Loan principal, for example 300,000, Annual interest rate (%), for example 6.5, and Loan term (years), for example 25.
- Optionally set First payment date, Recurring monthly extra, Recurring yearly extra, and Month for the yearly extra.
- Type a One-time lump sum together with the number in Lump sum on payment #.
- Click Calculate. At 300,000, 6.5%, 25 years, and +300/month you save 6 years 5 months and 91,174.74 of interest.
- A quick compare without the table lives on loan overpayment. One balance snapshot lives on loan balance after N payments.
Annuity schedule and extras in this table
A full annuity table plus an extras case. At 300,000, 6.5%, 25 years, and +300 a month you finish 6 years and 5 months sooner, and interest falls by 91,174.74.
- annuity
- The fixed principal-plus-interest row in this table. 300,000 at 6.5% for 25 years is the base versus 91,174.74 of interest saved.
- extras
- Payments above the scheduled installment, applied to principal. +300 a month cuts 91,174.74 of interest and 6 years 5 months.
- Interest saved
- Base interest minus the extras case. 91,174.74 on the first example. A yearly 6000 in December on 400,000 / 7% / 30 years saves 222,094.77.
Usage examples
Example 2
- Principal: 400,000
- Rate 7%, term 30 years
- First payment date: Jan 1, 2026
- Extra: 6,000/yr in December
10 yr 6 mo. earlier
Interest −222,094.77
A yearly December bonus of 6,000 (with a January start) shortens a 30-year loan by more than 10 years.
Example 3
- Principal: 200,000
- Rate 5.5%, term 20 years
- Lump sum: 15,000 on payment #24
2 yr 3 mo. earlier
Interest −22,880.72
A lump sum two years into the loan immediately lowers the principal and shortens the rest of the schedule.
Example 4
- 200,000
- 6%
- 20 years
- +200/mo
Schedule for 200,000 at 6% over 20 years with +200/mo
What does the schedule look like on 200,000 at 6% over 20 years with 200 extra a month? Schedule for 200,000 at 6% over 20 years with +200/mo.
Example 5
- 120,000
- 7.5%
- 12 years
- +100/mo
Schedule for 120,000 at 7.5% over 12 years with +100/mo
What does the schedule look like on 120,000 at 7.5% over 12 years with 100 extra a month? Schedule for 120,000 at 7.5% over 12 years with +100/mo.
When to use this calculator, and when to use a simpler one
- Choose Repayment schedule when you want the full month-by-month path: instalment, interest, principal, and remaining balance.
- If you only need a quick answer to “how much do I save by overpaying?”, the simpler Loan overpayment tool is better.
- If you just want to check how much remains after a number of instalments, Remaining balance is enough.
- If you have one debt amount and a fixed payment rather than a classic amortizing loan path, Debt repayment is the better fit.
Related calculators
FAQ
How much does +300 a month cut on 300,000 at 6.5% for 25 years?
6 years and 5 months. Interest falls by 91,174.74 versus the no-extra case.
What does 6,000 a year in December do on 400,000 at 7% for 30 years?
10 years and 6 months sooner and 222,094.77 less interest, with the January 1, 2026 start from the example.
What does 15,000 on payment 24 do on 200,000 at 5.5% for 20 years?
2 years and 3 months less and 22,880.72 less interest. You type the number in Lump sum on payment #.
Is this the file from an offer?
No. Fixed rate, no prepayment fee, no index reset. A teaching table, not the contract schedule.
How is this different from loan overpayment?
Here you see every payment. There you get one baseline-versus-scenario compare, without 300 rows. The same 500 extra can be checked on both.
Do I type the term in months?
The field is Loan term (years). 25 years stays 25. Month for the yearly extra is a separate January-December list.
Does the extra come off the annuity payment?
No. It goes to principal above the payment. The contractual installment stays, the balance falls faster, and the table shortens.
Does a comma in 6.5 work?
Yes. 6,5 and 6.5 are the same rate. Header currency only labels the result.
Where is the balance after 60 payments alone?
On loan balance after N payments. Here you get the whole table, not one cell.
Is 91,174.74 a guarantee from an offer?
No. It is a fixed-rate sketch. An offer may round differently and may add a fee. It is not a credit decision.
Knowledge sources
The schedule is a fixed-rate annuity from the rate you type. This is a sketch, not a contract.
Page updated in 2026.