Numbers from this site's public API on a 5-card $30,000 portfolio at 14-22% APR. The $2,800 reference is arithmetic, not an API output: $30,000 × 18.67% ÷ 2. Open the calculator with your own balances and rates and the rest comes out in real time.
The example portfolio
"Can I pay off $30,000 in six months" is the size where the monthly payment stops being a number you can find in a budget and becomes a number you have to construct. This page uses five US credit cards totalling $30,000 — the same five-card shape as the $30K in 1 year case study, so the two pages can be read side by side. Card A carries $8,000 at 22% APR with a $200 minimum; Card B $7,000 at 20% with a $175 minimum; Card C $6,000 at 18% with a $150 minimum; Card D $5,000 at 16% with a $125 minimum; Card E $4,000 at 14% with a $100 minimum. The five minimums add up to $750 a month.
The five APRs run a clean ladder from 22% down to 14%, and that matters for one number used all over this page: weighted by balance, the portfolio's rate is 18.67% a year — $8,000 × 22%, $7,000 × 20%, $6,000 × 18%, $5,000 × 16% and $4,000 × 14% come to $5,600 of annual interest on a $30,000 balance. One twelfth of that is 1.5556%, which on the opening balance is $466.67 for the first month.
To clear all five in six months, the snowball method needs $5,536 a month, which is $4,786 above the minimums. Avalanche needs slightly less — $5,470 — because it goes straight at the 22% card. Both land in month 6, and the thresholds are exact: at $5,535 the snowball plan slips to seven months, and avalanche's own cliff is $5,469. Every figure on this page is for the snowball plan unless it says otherwise.
What half a year of interest actually is
Everyone has an intuition that six months of debt costs half a year of interest. On this portfolio that intuition has a dollar value, and it is the yardstick the rest of the page is measured against. Take the $30,000, leave it exactly where it is, and let 18.67% run for six months: $30,000 × 18.67% ÷ 2 = $2,800.00. That is what half a year of interest means when nothing moves. Nobody actually pays it — but it is the right number to compare against, because it separates the two things that people confuse: the rate you are charged, and the balance you are charged it on.
| Same six months | Interest rolled up | Of the $30,000 | Of $2,800 |
|---|---|---|---|
| Balance never moves the yardstick | $2,800.00 | 9.33% | 100.00% |
| Minimums only, $750 a month | $2,734.93 | 9.12% | 97.68% |
| Six-month plan, $5,536 a month | $1,736.74 | 5.79% | 62.03% |
Read the bottom two rows against the top one and the whole page is there. Sending the $750 minimum does almost nothing to the interest: six months of it rolls up $2,734.93, which is 97.68% of the flat half-year. You are barely outrunning the rate — the monthly interest under minimums only walks from $466.67 down to $444.75 across the six months, a 4.7% decline in half a year. The six-month plan rolls up $1,736.74, 62.03% of the flat half-year, because the balance it is charged on is gone by month 6. Same debt, same six months, same rates: the only difference between 97.68% and 62.03% is how fast the balance died.
The plan row is also the only row whose payment is not a fixed amount, and that is worth spelling out because it is where the $1,479.26 sits. The plan's own payments run $5,536, $5,436, $5,311, $5,311, $5,161 and $4,981.74. Your $4,786 never moves; the $750 of minimums inside the payment does, because it is the sum of the minimums on the cards that still have a balance, and that floor gives way as cards are retired. Card E is gone after month 1, Card D after month 2, Card C after month 4 and Card B after month 5, so the floor walks down from $750 to $650, $525, $525, $375 and finally the single $200 left on Card A. Add the six real payments and you get $31,736.74 — $1,479.26 below the naive six equal payments of $33,216.
The same six months, on minimums only
Sending $750 a month clears this portfolio in 73 months — just over six years — and costs $18,014.10 in interest, a total bill of $48,014.10. The six-month plan's $1,736.74 is 9.64% of that, a saving of $16,277.36.
The same-term comparison is the sharper one, because both plans are spending the same six months. The minimums move $4,500 out of your account, of which $2,734.93 is interest and only $1,765.07 reaches principal, leaving $28,234.93 still owed. The six-month plan sends $31,736.74 over the same six months and ends the debt. Put the two side by side and the plan's $1,736.74 is 63.50% of the $2,734.93 the minimums roll up — and six months of minimums pay 1.57 times the interest the entire six-month plan costs — you can pay more interest in half a year than a working plan charges from start to finish, and the only variable that decides which happens is the size of the payment.
What the plan costs, and what the method is worth
On this portfolio the interest bill is $1,736.74 on the snowball method and $1,503.17 on the avalanche, a gap of $233.57 — 13.45% of the interest bill. The total that leaves your account is $31,736.74, which is the $30,000 balance plus the interest, so the interest is 5.47% of everything you send and 5.79% of the balance you started with. Both are worth keeping straight, because the second one is the number that answers "what does six months of debt cost me" and the first one is the number that answers "what share of my payments was rent". Against a full year at the blended rate the plan's $1,736.74 is 31.01% of the $5,600 an untouched $30,000 would be charged in twelve months.
What the method changes is the order the cards leave in. Snowball clears Card E in month 1, Card D in month 2, Card C in month 4, Card B in month 5 and Card A in month 6. Avalanche clears Card A in month 2, then Card B in month 4, Card C in month 5, and finishes Card D and Card E together in month 6. Both are debt-free at month 6; avalanche gets there with $233.57 less interest, which is real money but is 13.45% of a bill that a working plan has already held down to 62.03% of the flat half-year.
Where the $4,786 comes from
This is the part that decides whether the plan happens, so it is worth stating plainly: you need $4,786 a month above the $750 you already pay, and over the six months that is $28,711.74 — 95.71% of the original balance. At $20 an hour after tax it is roughly 55 extra hours a week, which is more than a second job. At this size a six-month payoff is almost never a budgeting exercise; it is funded from the top of a short list — a vehicle, a second property or an inheritance turned into cash, a fixed-term contract, or a retirement-contribution pause above the match — and usually from more than one of them.
Two things soften it. The floor gives way on its own, so the plan payment is under $5,200 from month 5 without you changing anything, and the last payment is $4,981.74. And the deadline is forgiving in a way the balance is not: if you can only find $3,500 of new money instead of $4,786, the plan stretches past six months rather than failing, and every month you do fund still costs a fraction of what minimums-only charges on the same balance — 62.03% of the flat half-year versus 97.68%.
Reproduce these numbers
Every figure on this page except the $2,800 reference comes from this site's public API. Post the five balances, their rates, their minimums and extra: 4786 to /api/payoff and you get the same months, the same $1,736.74 and the same per-card breakdown. Two things that trip people up: APR goes in as a percentage (22, not 0.22), and extra is the amount above your total minimums, not your total payment — $4,786 here, which is what turns the $750 in minimums into $5,536 a month. The $2,800 is not in the API because it is not a payoff plan: it is $30,000 × 18.67% ÷ 2, the cost of six months with nothing moving. Or just open the calculator and type your balances in — same engine, no payload.
If your target is a different size or a different deadline, the same analysis is in the $30K in 1 year, $20K in 6 months, $5K in 6 months, $10K in 6 months, $15K in 6 months, $5K in 1 year, $10K, $15K, $20K, $25K, $40K, $50K and $100K case studies, plus a 36-second walkthrough of the $25K case on YouTube. Shorter answers to the most common payoff questions live in the payoff questions hub.
Frequently asked
How much do I have to pay a month to clear $30,000 in six months?
On the five-card example here, $5,536 a month clears the $30,000 in six months on the snowball method, which is $4,786 above the $750 in minimums. Avalanche needs less — $5,470 — because it goes at the 22% card first. Both land in month 6, and the snowball threshold is exact: at $5,535 the same portfolio takes seven months, and avalanche's own cliff is $5,469.
How much interest do I pay on $30,000 over six months?
$1,736.74 on the snowball method and $1,503.17 on the avalanche, a gap of $233.57 which is 13.45% of the interest bill. The interest is 5.79% of the original $30,000. The total that leaves your account over the six months is $31,736.74 on snowball — the $30,000 balance plus $1,736.74 of interest.
Is six months of interest really half a year of interest?
No, not once you are paying. A balance that never moved would be charged $2,800.00 for six months at this portfolio's balance-weighted 18.67% APR, which is $30,000 × 18.67% ÷ 2. The six-month plan pays $1,736.74, which is 62.03% of that $2,800 and 5.79% of the $30,000. Six months of minimum payments pay $2,734.93, which is 97.68% of the $2,800 — the minimums really do cost you the whole half-year.
Why is the payment $5,536 in month 1 and less later on?
Because only part of the plan payment is fixed. Your own $4,786 never moves, but the $750 of minimums inside it is the sum of the minimums on the cards that still have a balance, and that floor gives way as cards are retired — Card E after month 1, Card D after month 2, Card C after month 4 and Card B after month 5 — so the floor walks from $750 to $650, $525, $525, $375 and finally the single $200 left on Card A. The monthly total therefore runs $5,536, $5,436, $5,311, $5,311, $5,161 and $4,981.74, which adds to $31,736.74 and is $1,479.26 below the naive six equal payments of $33,216.
Does snowball versus avalanche matter on $30,000 over six months?
It is worth $233.57 over the six months, which is 13.45% of the interest bill. Avalanche pays $1,503.17 and snowball pays $1,736.74. The payoff orders are genuinely different — snowball clears Card E then Card D then Card C then Card B then Card A, avalanche clears Card A first and finishes on Card D and Card E together — but both methods reach zero in month 6.
What if I only pay the minimums on $30,000?
The $750 in minimums clears the balance in 73 months — just over six years — and costs $18,014.10 in interest, a total bill of $48,014.10. Over the same six months the minimums move $4,500 out of your account, pay $2,734.93 of interest and retire only $1,765.07 of principal, leaving $28,234.93 still owed. The six-month plan's $1,736.74 is 9.64% of the minimums-only interest, a saving of $16,277.36.
What is the blended interest rate on this portfolio?
18.67% a year, weighted by balance: $8,000 at 22%, $7,000 at 20%, $6,000 at 18%, $5,000 at 16% and $4,000 at 14% work out to $5,600 of annual interest on $30,000. One month of that is 1.5556%, which is $466.67 on the opening balance — and $466.67 divided by $30,000 is exactly 18.67% divided by twelve. By month 6, under the plan, the monthly interest is down to $89.69.
How much new money do I have to find each month for a six-month $30,000 payoff?
$4,786 a month above the $750 you are already paying, which over the six months comes to $28,711.74 — 95.71% of the original balance. The total payment drifts down without you doing anything because the minimums floor gives way, from $5,536 in month 1 to $4,981.74 in month 6. At $20 an hour after tax that is roughly 55 extra hours a week, so in practice this is funded by an asset sale or a windfall plus a temporary income push, not by trimming a budget.