One $5,000 card at 24% APR, $125 minimum held fixed, no extra payments, no new charges. Numbers from this site's public payoff engine.
Month one: $25 of your $125 is principal
The interest is not a fee bolted on top of the balance; it is 2% of the balance, because 24% a year is 2% a month. At $5,000 that is $100. The $125 minimum pays the interest first, and $25 is what is left to reduce the balance. That is the whole mechanism, and it repeats every month against a slightly smaller balance: $99.50 of interest and $25.50 of principal in month 2, $98.99 and $26.01 in month 3.
Twelve months of that is in the table below, cent for cent, with the balance column on the right so you can see how little of it moves.
| Month | Payment | Interest | Principal | Balance left |
|---|---|---|---|---|
| 1 | $125.00 | $100.00 | $25.00 | $4,975.00 |
| 2 | $125.00 | $99.50 | $25.50 | $4,949.50 |
| 3 | $125.00 | $98.99 | $26.01 | $4,923.49 |
| 4 | $125.00 | $98.47 | $26.53 | $4,896.96 |
| 5 | $125.00 | $97.94 | $27.06 | $4,869.90 |
| 6 | $125.00 | $97.40 | $27.60 | $4,842.30 |
| 7 | $125.00 | $96.85 | $28.15 | $4,814.14 |
| 8 | $125.00 | $96.28 | $28.72 | $4,785.43 |
| 9 | $125.00 | $95.71 | $29.29 | $4,756.13 |
| 10 | $125.00 | $95.12 | $29.88 | $4,726.26 |
| 11 | $125.00 | $94.53 | $30.47 | $4,695.78 |
| 12 | $125.00 | $93.92 | $31.08 | $4,664.70 |
Twelve months of minimums retires $335.29
You have sent $1,500 and the balance has moved from $5,000 to $4,664.70. Of the $1,500, $1,164.71 was interest — 77.6%. The principal column is not stuck, it is just growing slowly: $25.00 in month 1, $31.08 in month 12, which is a 24% increase in the part of the payment that does any work. That growth is the only reason the card ever clears.
The crossover is month 48
Month 48 is the first month where the principal beats the interest: $63.41 against $61.59, with $3,016.16 still owed. Month 47 is the last one the other way round, $62.17 against $62.83. Four years of on-time minimums to reach the point where a payment finally does more than the interest is charging.
The interest bill front-loads in the same way. Half of all the interest this card will ever charge — $2,579.75 of $5,159.49 — is already paid by month 29. By month 36 it is 62.0%. The balance at that point is still $3,700.14, so you have paid $4,500 to remove $1,299.86 of debt.
The second half is the mirror image
Nothing about the payment changes — it is $125 every month — but the share of it that reaches the balance climbs steadily. Here is the same 82 months cut into bands, with the balance at the end of each one.
| Months | Principal share | Balance at end | What it looks like |
|---|---|---|---|
| 1–12 | 22.4% | $4,664.70 | the balance barely moves |
| 13–24 | 28.4% | $4,239.45 | $760 of the original $5,000 gone |
| 25–36 | 36.0% | $3,700.14 | a third of each payment is principal |
| 37–48 | 45.6% | $3,016.16 | the crossover month lands here |
| 49–60 | 57.8% | $2,148.71 | more than half is principal |
| 61–72 | 73.3% | $1,048.57 | the balance finally looks small |
| 73–82 | 90.4% | $0.00 | ten months, almost all principal |
The last twelve months retire $1,250.57 of principal against $158.93 of interest — 88.7% principal — which is more principal than the first twenty-four months managed ($760.55). The final payment is $34.49, because there is almost nothing left for it to pay.
Why the same $125 does two different jobs
Two things are moving in opposite directions. The interest is a fixed percentage of a shrinking balance, so it falls. The payment is fixed, so every dollar of interest that disappears becomes a dollar of principal. The two curves cross in month 48, and after that the payment is doing more work each month than the month before, which is why the last ten months can retire $1,048.59 on the same $125.
This is not a trick of this card. It is the arithmetic of any fixed payment against any rate, which is why the $10,000 version of this page shows the same shape with bigger numbers, and why the APR itself moves the crossover month earlier or later without changing the shape at all.
The lever that beats every schedule choice
On one card there is no order to argue about — nothing to sort by balance or by rate — so the amount is the only lever, and it is a big one. Adding $50 a month takes the same card from 82 months to 43 and from $5,159.49 of interest to $2,488.04: $2,671.45 and 39 months. Adding $100 takes it to 30 months and $1,678.99. What the second $25 buys, and what waiting a year to start costs takes that lever apart.
For scale, the whole argument between paying the smallest card first and paying the most expensive card first was worth $30,074.90 across twelve portfolios. One extra $50 on a single $5,000 card is worth $2,671.45. The order is free to change and worth having, but the amount is what moves the date. What each extra level buys runs the same numbers across four cards.
Reproduce these numbers
Post the card and zero extra to /api/payoff and the response gives you the months, the total interest and the month-by-month timeline this page is built from. The payload is {"debts": [{"name": "Card", "balance": 5000, "apr": 24, "minPayment": 125}], "extra": 0} — it returns 82 months and $5,159.49. Two conventions: APR goes in as a percentage (24, not 0.24), and minPayment is held fixed for the whole run. Real issuers often recalculate it as a percentage of the balance, which lowers the payment over time and lengthens the schedule; holding it fixed keeps this page comparable with every other page here.
Frequently asked
How much of my minimum payment goes to principal?
On a $5,000 card at 24% with a $125 minimum, $25 of the first payment is principal and $100 is interest. Twelve months in the split has moved to $31.08 of principal, with $335.29 retired against $1,500 paid. The payment does not become more than half principal until month 48.
Why does so little of the payment go to principal at first?
Because interest is charged on the whole balance before anything reaches it. At 24% APR the monthly rate is 2%, so a $5,000 balance is charged $100 in month 1 and only the remaining $25 of the $125 touches the balance. The same $125 retires more each month as the balance behind it shrinks.
When does more than half of the payment become principal?
Month 48. That month the interest is $61.59 and the principal is $63.41, with $3,016.16 still owed. Until then every payment is majority interest, which is why the first four years of minimums feel like the balance is not moving.
How long does $5,000 at 24% take if I only pay the minimum?
82 months, and $5,159.49 of interest on a $5,000 balance — $10,159.49 in total, or 2.03 times what you borrowed. The balance does not drop below $1,000 until month 73.
Does the minimum payment go down as the balance falls?
Many issuers recalculate the minimum as a percentage of the balance, so it does fall, and that makes the real payoff slower than the schedule on this page rather than faster. This page holds the $125 fixed, the same convention every page on this site uses, so the comparison stays clean.
How much faster is it if I add $50 a month?
43 months instead of 82, and $2,488.04 of interest instead of $5,159.49 — $2,671.45 and 39 months saved. Adding $100 a month takes it to 30 months and $1,678.99. On a single card there is no order to argue about, so the amount is the only lever.