Existing Loan Calculator
Already partway through a loan? Enter its original terms and how many payments you have made to see your current balance and how much interest is left.
A worked example
Running this tool on current national benchmarks (Federal Reserve / Freddie Mac via FRED (St. Louis Fed)) — swap in your own numbers to see how the result moves.
- Original loan amount
- $200,000
- Interest rate
- 6%
- Original term (years)
- 30
- Payments already made
- 60
after 60 payments of $1,199.10
- Principal paid so far$13,891
- Interest paid so far$58,055
- Remaining balance$186,109
How the current balance changes with payments already made
Holding the other inputs at the example above, here is how the result moves as payments already made changes.
| Payments already made | Current balance | Principal paid so far |
|---|---|---|
| 12 | $197,544 | $2,456 |
| 60 | $186,109 | $13,891 |
| 120 | $167,371 | $32,629 |
| 240 | $108,007 | $91,993 |
The math behind it
The calculator rebuilds the full amortization schedule from your original loan amount, rate and term, then jumps to the point corresponding to the number of payments you have already made. It reads off the balance at that point, along with how much principal and interest you have paid so far, and computes the interest still remaining. Because early payments are mostly interest, the principal paid down after a given number of payments is often smaller than borrowers expect.
Assumptions & limits
- The loan followed its original fixed schedule with no missed, extra or partial payments.
- The current balance and split of principal versus interest come from the point in the amortization schedule matching your payments made.
- A fixed interest rate is assumed for the whole term.
- Escrow items such as taxes and insurance are excluded — this tracks principal and interest only.
Common questions
Why have I paid down so little principal so far?
Because amortization front-loads interest. In the early years, most of each payment covers the interest on a large outstanding balance, leaving only a little for principal. This calculator shows the actual principal-versus-interest split at your current point, which is usually more interest-heavy than it feels.
How much interest do I still have left to pay?
It is the total interest over the original schedule minus the interest you have already paid. The calculator reports this remaining-interest figure directly, so you can see the full future cost of staying on the current schedule versus paying extra or refinancing.
Does this account for extra payments I've made?
No. It assumes you followed the original schedule exactly. If you have made extra principal payments, your real balance is lower than shown. Use it as a baseline for a loan paid on schedule, then compare against your latest statement.