A prepayment penalty is a fee some lenders charge when you pay off all or part of a mortgage early — typically on a sale or a refinance within the first few years. The Consumer Financial Protection Bureau's explanation of prepayment penalties describes exactly that, and notes that not every mortgage has one and that small extra principal payments usually do not trigger it, though you should confirm that with your own lender.
That last point is the reason this page from Arb Digital is built the way it is. There is no standard penalty. The method, the size, the free allowance and the window are all written into a specific contract, and they vary between lenders, between loan types and between jurisdictions. So this mortgage prepayment penalty calculator publishes no schedule and no rates. Every rule comes from you, out of your own loan documents.
What This Calculator Does
Pick the method your note specifies, enter its numbers, and the tool works out how much of your intended prepayment is actually chargeable after any penalty-free allowance, what the penalty on that amount would be, what proportion of the prepayment that represents, and how long a refinance would take to break even once the penalty is added to the closing costs.
It supports the four shapes that appear in practice: a number of months' interest, a percentage of the amount prepaid, an interest rate differential, and a flat fee. It does not tell you which one applies to you. Your note does that, and where the note and this page disagree, the note governs.
How to Use It
- Find the prepayment clause in your loan documents. It is usually a named section in the note or a separate rider, and it will state both the method and the window during which it applies.
- Check whether the allowance is on the original or current balance. The difference is large on a seasoned loan, and lenders word it both ways.
- Enter only the fields your method uses. The others are ignored, so you can leave them at their defaults.
- Ask for a payoff statement. Lenders produce a written figure valid to a stated date. That figure, not this estimate, is what you will pay.
- Compare against the refinance you are actually offered. The break-even output is only as good as the monthly saving and closing costs you enter.
How Each Method Is Calculated
First the tool works out the chargeable amount: the penalty-free allowance is the allowance percentage applied to the original loan amount, and anything you prepay beyond that is chargeable. With the defaults, 15% of $400,000 is $60,000, so prepaying the full $320,000 balance leaves $260,000 chargeable.
Months of interest: chargeable amount × annual rate ÷ 12 × the number of months. Here, $260,000 × 6.5% ÷ 12 × 3 = $4,225. Percentage: chargeable amount × the stated percentage, so 2% of $260,000 = $5,200. Flat fee: the figure you enter, unchanged. Interest rate differential: chargeable amount × the rate gap × the remaining term in years, so $260,000 × (6.5% − 4.9%) × 2.5 = $10,400.
That comparison is the important one. On identical facts, the simple three-months-interest method produces $4,225 and the differential method produces $10,400 — nearly two and a half times as much. Which one you face is a matter of what your contract says, not of what is reasonable, and it is the first thing to check before assuming an early payoff is cheap.
Why the Interest Rate Differential Is the One to Watch
A differential penalty is designed to compensate the lender for the interest it will not now receive, so it grows with both the size of the rate gap and the time left in the term. When market rates have fallen a long way below your contract rate — precisely the situation that makes refinancing attractive — the differential is at its largest. The penalty is, by construction, worst exactly when you most want to leave.
Lenders also differ in how they compute it. Some use a posted rate for the remaining term, some adjust for any discount you originally received, and some present-value the shortfall rather than summing it. Those choices can move the figure substantially, which is why the comparison rate on this page is an input rather than something the tool selects. If your lender's method involves discounting, treat the simple product used here as an upper-bound sketch and rely on the payoff statement.
Restrictions Differ by Jurisdiction and Loan Type
Prepayment penalties are regulated, and in some places restricted or prohibited outright. In the United States, 12 CFR § 1026.43 limits when a prepayment penalty may be imposed on covered dwelling-secured transactions at all, and caps both its size and how long it may last. Several government-backed loan programmes do not permit them, and a number of states impose their own further limits.
Elsewhere the picture is different again: some markets treat a differential charge as normal on a fixed-rate term, others cap penalties by statute, and others exclude variable-rate loans. The practical rule is that neither a general web page nor a rule of thumb tells you what applies to your loan. Your note tells you, your lender confirms it in a payoff statement, and a licensed adviser or attorney in your jurisdiction can tell you whether the clause is enforceable as written.
The Break-Even Calculation That Actually Matters
Most refinance arithmetic divides closing costs by monthly saving and calls the result the break-even. That omits the penalty on the loan you are leaving, which is often the largest single number in the transaction. With the defaults, $3,000 of closing costs against a $260 monthly saving breaks even in 11.5 months. Add the $4,225 penalty and it becomes 27.8 months — and under the differential method it would be 51.5 months.
The consequence is straightforward: a refinance that looks obviously worthwhile on closing costs alone can be marginal or negative once the exit penalty is included, particularly if you expect to sell or move within a few years. Our refinance break-even calculator handles the closing-cost side in more depth and deliberately does not model the penalty on the old loan; this page fills that gap, and the two are meant to be read together with the mortgage refinance calculator.
Ways the Penalty Can Be Avoided or Reduced
Three patterns come up often enough to be worth knowing about, all of which depend entirely on your contract. The first is the free allowance: many notes permit a percentage of the balance to be repaid each year without charge, so splitting a large lump sum across two annual periods can reduce or eliminate the chargeable amount. The second is the expiry window — penalties commonly apply only for the first few years, so waiting until the window closes may cost less than the penalty would. The third is portability, where a lender lets you carry the existing loan to a new property instead of paying it off.
None of these is universal and none should be assumed. Confirm each in writing with the lender before planning around it. If you are timing a lump sum, our extra payment loan calculator and mortgage payoff calculator show what the payments themselves achieve, and the mortgage amortization calculator shows how much interest remains in the schedule you would be leaving.
Arb Digital publishes an open library of finance and business calculators. Every one states its formula on the page and takes its numbers from you.
Browse All Free Tools Contact Arb DigitalCommon Mistakes to Avoid
- Assuming there is no penalty because nobody mentioned one — the clause is in the documents whether or not it was discussed at closing.
- Applying the free allowance to the wrong balance, since notes express it against the original amount or the current balance and the difference can be tens of thousands.
- Using a three-months-interest estimate when your note specifies a differential, which can understate the charge several times over.
- Leaving the penalty out of a refinance break-even, which is the single most common way a refinance looks better than it is.
- Planning around a verbal quote instead of a written payoff statement valid to a specific date.
Related Free Tools From Arb Digital
Pair this with the refinance break-even calculator and the mortgage refinance calculator for the new-loan side. For the existing loan, see the mortgage payoff calculator, the extra payment loan calculator and the mortgage amortization calculator. When comparing offers, the loan comparison calculator and the mortgage points calculator help. Everything else is in the free online tools hub.
Frequently Asked Questions
It is a fee some lenders charge when you pay off all or part of a mortgage early, usually within the first few years and typically triggered by a sale or a refinance. Not every mortgage has one, and the terms are set entirely by the loan contract.
It depends on the method your note specifies. Common forms are a set number of months' interest on the amount prepaid, a percentage of that amount, an interest rate differential, or a flat fee. Only your loan documents determine which applies.
It charges the gap between your contract rate and a comparison rate, applied to the amount prepaid over the remaining term. It grows as market rates fall further below your rate, so it is largest exactly when refinancing looks most attractive.
Usually not, and the CFPB notes that penalties do not normally apply to small extra principal payments made a bit at a time. Many notes also allow a set percentage each year without charge, but you should confirm both with your own lender.
No. They are regulated, and some jurisdictions restrict or prohibit them. In the United States, federal rules limit when a penalty may be imposed on covered dwelling-secured loans and cap its size and duration, and several loan programmes and states go further.
Yes. Leaving it out is the most common reason a refinance looks better than it is. Add the penalty to the closing costs before dividing by the monthly saving, which is what this page does.
Ask your lender for a written payoff statement valid to a specific date. That figure governs, and it will reflect the actual clause, the timing and any allowance you have already used.
This tool performs arithmetic on penalty rules you enter from your own loan documents. It publishes no penalty schedules, rates or fees of its own, and it is not financial or legal advice. Your promissory note and your lender govern what you will actually be charged, restrictions on prepayment penalties differ by jurisdiction and by loan type, and you should obtain a written payoff statement and, where the amounts are significant, advice from a licensed adviser or attorney before acting.
