Mortgage overpayment calculator
Enter the balance left, the rate and the months left, then what you add each month and/or a sum paid now. The monthly payment stays the same: the term gets shorter.
Result
16,767.50Interest saved
- Current monthly payment (unchanged)
- 1,159.92
- Months saved
- 47
- New term: 16 years and 1 months
- Interest left without overpaying
- 78,380.66
- Interest left with overpayments
- 61,613.16
- Last payment
- January 5, 2043
Year by year
Detailed table
| Year | Principal repaid | Interest paid | Left to pay |
|---|---|---|---|
| 1 | 9,469.99 | 6,849.04 | 190,530.01 |
| 2 | 19,276.80 | 13,361.27 | 180,723.20 |
| 3 | 29,432.40 | 19,524.70 | 170,567.60 |
| 4 | 39,949.21 | 25,326.92 | 160,050.79 |
| 5 | 50,840.07 | 30,755.09 | 149,159.93 |
| 6 | 62,118.29 | 35,795.91 | 137,881.71 |
| 7 | 73,797.64 | 40,435.60 | 126,202.36 |
| 8 | 85,892.38 | 44,659.88 | 114,107.62 |
| 9 | 98,417.30 | 48,454.00 | 101,582.70 |
| 10 | 111,387.69 | 51,802.64 | 88,612.31 |
| 11 | 124,819.40 | 54,689.96 | 75,180.60 |
| 12 | 138,728.84 | 57,099.56 | 61,271.16 |
| 13 | 153,132.99 | 59,014.44 | 46,867.01 |
| 14 | 168,049.45 | 60,417.01 | 31,950.55 |
| 15 | 183,496.45 | 61,289.05 | 16,503.55 |
| 16 | 199,492.85 | 61,611.68 | 507.15 |
| 17 | 200,000.00 | 61,613.16 | 0.00 |
How it is calculated
- Current payment = balance × i ÷ (1 − (1 + i)^−n), with i = rate ÷ 12 and n = months left.
- The lump sum lowers the balance; then each month you pay the payment + the extra.
- Interest saved = interest without extra − interest with extra.
Example
200,000 left at 3.5% over 240 months, with 200 extra a month: payment 1,159.92, paid off in 193 months (47 months saved) and 16,767.50 of interest saved.
Good to know
- Early repayment charges are not included: they depend on your contract (and your country’s law).
- Fixed rate; insurance and fees not included.
Frequently asked questions
What is this tool used for?
Enter the balance left, the rate and the months left, then what you add each month and/or a sum paid now. The monthly payment stays the same: the term gets shorter.
How is the result calculated?
Current payment = balance × i ÷ (1 − (1 + i)^−n), with i = rate ÷ 12 and n = months left.
What should I check before using the result?
Early repayment charges are not included: they depend on your contract (and your country’s law).