Income-Driven vs Standard Repayment
The IDR trade-off on $45,000 at 6.5%: the standard 10-year plan versus a 20-year income-driven-style repayment. A pre-filled student loan calculator scenario.
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Your loan details
Interest accrues and capitalizes during grace
Applied 100% to principal
Results
Base payment
$511
Actual payment
$511
Total interest
$16,316
Interest saved
$0
Payoff time
120 months
Scheduled term, no extra payments
Total repayment
$61,316
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Balance & interest over time
Month-by-month breakdown
| Month | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $511 | $267 | $244 | $44,733 |
| 2 | $511 | $269 | $242 | $44,464 |
| 3 | $511 | $270 | $241 | $44,194 |
| 4 | $511 | $272 | $239 | $43,922 |
| 5 | $511 | $273 | $238 | $43,649 |
| 6 | $511 | $275 | $236 | $43,375 |
| 7 | $511 | $276 | $235 | $43,099 |
| 8 | $511 | $278 | $233 | $42,821 |
| 9 | $511 | $279 | $232 | $42,542 |
| 10 | $511 | $281 | $230 | $42,262 |
| 11 | $511 | $282 | $229 | $41,980 |
| 12 | $511 | $284 | $227 | $41,696 |
| 13 | $511 | $285 | $226 | $41,411 |
| 14 | $511 | $287 | $224 | $41,124 |
| 15 | $511 | $288 | $223 | $40,836 |
| 16 | $511 | $290 | $221 | $40,546 |
| 17 | $511 | $291 | $220 | $40,255 |
| 18 | $511 | $293 | $218 | $39,962 |
| 19 | $511 | $295 | $216 | $39,668 |
| 20 | $511 | $296 | $215 | $39,372 |
| 21 | $511 | $298 | $213 | $39,074 |
| 22 | $511 | $299 | $212 | $38,775 |
| 23 | $511 | $301 | $210 | $38,474 |
| 24 | $511 | $303 | $208 | $38,171 |
| 25 | $511 | $304 | $207 | $37,867 |
| 26 | $511 | $306 | $205 | $37,561 |
| 27 | $511 | $308 | $203 | $37,253 |
| 28 | $511 | $309 | $202 | $36,944 |
| 29 | $511 | $311 | $200 | $36,633 |
| 30 | $511 | $313 | $198 | $36,321 |
| 31 | $511 | $314 | $197 | $36,007 |
| 32 | $511 | $316 | $195 | $35,691 |
| 33 | $511 | $318 | $193 | $35,373 |
| 34 | $511 | $319 | $192 | $35,054 |
| 35 | $511 | $321 | $190 | $34,733 |
| 36 | $511 | $323 | $188 | $34,410 |
| 37 | $511 | $325 | $186 | $34,085 |
| 38 | $511 | $326 | $185 | $33,759 |
| 39 | $511 | $328 | $183 | $33,431 |
| 40 | $511 | $330 | $181 | $33,101 |
| 41 | $511 | $332 | $179 | $32,769 |
| 42 | $511 | $333 | $178 | $32,436 |
| 43 | $511 | $335 | $176 | $32,100 |
| 44 | $511 | $337 | $174 | $31,763 |
| 45 | $511 | $339 | $172 | $31,424 |
| 46 | $511 | $341 | $170 | $31,084 |
| 47 | $511 | $343 | $168 | $30,741 |
| 48 | $511 | $344 | $167 | $30,397 |
| 49 | $511 | $346 | $165 | $30,050 |
| 50 | $511 | $348 | $163 | $29,702 |
| 51 | $511 | $350 | $161 | $29,352 |
| 52 | $511 | $352 | $159 | $29,000 |
| 53 | $511 | $354 | $157 | $28,646 |
| 54 | $511 | $356 | $155 | $28,290 |
| 55 | $511 | $358 | $153 | $27,933 |
| 56 | $511 | $360 | $151 | $27,573 |
| 57 | $511 | $362 | $149 | $27,211 |
| 58 | $511 | $364 | $147 | $26,848 |
| 59 | $511 | $366 | $145 | $26,482 |
| 60 | $511 | $368 | $143 | $26,115 |
| 61 | $511 | $370 | $141 | $25,745 |
| 62 | $511 | $372 | $139 | $25,374 |
| 63 | $511 | $374 | $137 | $25,000 |
| 64 | $511 | $376 | $135 | $24,625 |
| 65 | $511 | $378 | $133 | $24,247 |
| 66 | $511 | $380 | $131 | $23,867 |
| 67 | $511 | $382 | $129 | $23,486 |
| 68 | $511 | $384 | $127 | $23,102 |
| 69 | $511 | $386 | $125 | $22,716 |
| 70 | $511 | $388 | $123 | $22,328 |
| 71 | $511 | $390 | $121 | $21,938 |
| 72 | $511 | $392 | $119 | $21,546 |
| 73 | $511 | $394 | $117 | $21,152 |
| 74 | $511 | $396 | $115 | $20,756 |
| 75 | $511 | $399 | $112 | $20,357 |
| 76 | $511 | $401 | $110 | $19,956 |
| 77 | $511 | $403 | $108 | $19,553 |
| 78 | $511 | $405 | $106 | $19,148 |
| 79 | $511 | $407 | $104 | $18,741 |
| 80 | $511 | $409 | $102 | $18,332 |
| 81 | $511 | $412 | $99 | $17,920 |
| 82 | $511 | $414 | $97 | $17,506 |
| 83 | $511 | $416 | $95 | $17,090 |
| 84 | $511 | $418 | $93 | $16,672 |
| 85 | $511 | $421 | $90 | $16,251 |
| 86 | $511 | $423 | $88 | $15,828 |
| 87 | $511 | $425 | $86 | $15,403 |
| 88 | $511 | $428 | $83 | $14,975 |
| 89 | $511 | $430 | $81 | $14,545 |
| 90 | $511 | $432 | $79 | $14,113 |
| 91 | $511 | $435 | $76 | $13,679 |
| 92 | $511 | $437 | $74 | $13,242 |
| 93 | $511 | $439 | $72 | $12,803 |
| 94 | $511 | $442 | $69 | $12,361 |
| 95 | $511 | $444 | $67 | $11,917 |
| 96 | $511 | $446 | $65 | $11,470 |
| 97 | $511 | $449 | $62 | $11,022 |
| 98 | $511 | $451 | $60 | $10,570 |
| 99 | $511 | $454 | $57 | $10,117 |
| 100 | $511 | $456 | $55 | $9,660 |
| 101 | $511 | $459 | $52 | $9,202 |
| 102 | $511 | $461 | $50 | $8,741 |
| 103 | $511 | $464 | $47 | $8,277 |
| 104 | $511 | $466 | $45 | $7,811 |
| 105 | $511 | $469 | $42 | $7,342 |
| 106 | $511 | $471 | $40 | $6,871 |
| 107 | $511 | $474 | $37 | $6,397 |
| 108 | $511 | $476 | $35 | $5,921 |
| 109 | $511 | $479 | $32 | $5,442 |
| 110 | $511 | $481 | $29 | $4,961 |
| 111 | $511 | $484 | $27 | $4,477 |
| 112 | $511 | $487 | $24 | $3,990 |
| 113 | $511 | $489 | $22 | $3,501 |
| 114 | $511 | $492 | $19 | $3,009 |
| 115 | $511 | $495 | $16 | $2,514 |
| 116 | $511 | $497 | $14 | $2,016 |
| 117 | $511 | $500 | $11 | $1,516 |
| 118 | $511 | $503 | $8 | $1,014 |
| 119 | $511 | $505 | $5 | $508 |
| 120 | $511 | $508 | $3 | $0 |
Features
- Monthly payment estimate
- Grace-period interest capitalization
- Extra-payment savings (time & interest)
- Month-by-month repayment schedule
- Shareable result card + CSV export
Scenario Benchmark
Key figures for Income-Driven vs Standard Repayment.
Base payment
$511
Total interest
$16,316
Total repayment
$61,316
Frequently asked questions
How the maths works
A student loan is a fixed-rate amortizing loan. A grace period lets interest accumulate and capitalize before payments start, so the balance you repay can exceed what you borrowed.
- 1During the grace period, monthly interest accrues on the balance and is capitalized (added to principal) when repayment begins.
- 2Base payment M = L·r / (1 − (1+r)^−n), where L is the capitalized balance, r the monthly rate and n the term in months.
- 3Each month, interest = balance·r and the rest of the payment reduces principal.
- 4An extra monthly payment goes 100% to principal, shortening the term and cutting total interest.
Figures are illustrative and exclude fees, deferment and forgiveness programs. Not financial advice.
Everything you need to know
What is interest capitalization?
During a grace period (typically six months after graduation), no payments are due but interest keeps accruing on unsubsidized loans.
When repayment starts, that accrued interest is added to your principal — you then pay interest on interest, which is why the balance can grow before you make a single payment.
Extra payments are the fastest lever
Every extra dollar you pay goes straight to principal, which cuts future interest and shortens the term — often by years.
The calculator shows exactly how many months (and how much interest) an extra monthly payment saves on your specific loan.
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