★ MONEY · LOANS · PERSONAL LOANS
A $15,000 loan at 10.5% for 48 months costs $384.05 a month. The total paid is $18,434.43 and the interest is $3,434.43. Enter your loan amount, APR and term to work out your payment, your total and your interest.
A personal loan is priced on three numbers: how much you borrow, the APR, and how many months you take to repay it. The monthly payment follows the standard loan formula, the total paid is the payment times the months, and the interest is the total minus the loan. This calculator works out all three, plus what the first payment is made of and how much interest the first and last years cost, so the number you get is the number on the loan.
A personal loan payment is priced on three numbers: how much you borrow, the APR, and how many months you take to repay it. The monthly rate is the APR divided by 12, the number of payments is the months, and the payment is the loan times the monthly rate times (1 + rate) to the power of the payments, divided by (1 + rate) to the power of the payments minus 1. The total paid is the payment times the number of payments, and the interest is the total paid minus the loan.
At the defaults — loan $15,000, APR 10.5%, term 48 months — the monthly rate is 10.5% ÷ 12 = 0.875%, the payments are 48, and the payment is $384.05 a month. The total paid is $384.05 × 48 = $18,434.43, and the interest is $18,434.43 − $15,000 = $3,434.43. The first payment is $131.25 interest and $252.80 principal, the first year costs $1,424.66 of interest, and the last year costs $251.75.
| Case | Monthly payment | Total paid | Interest |
|---|---|---|---|
| Default ($15,000, 10.5%, 48 mo) | $384.05 | $18,434.43 | $3,434.43 |
| $10,000 loan | $256.03 | $12,289.62 | $2,289.62 |
| $25,000 loan | $640.08 | $30,724.06 | $5,724.06 |
| APR 7% | $359.19 | $17,241.30 | $2,241.30 |
| APR 15% | $417.46 | $20,038.14 | $5,038.14 |
| Term 24 months | $695.64 | $16,695.37 | $1,695.37 |
| Term 60 months | $322.41 | $19,344.51 | $4,344.51 |
| Term 72 months | $281.68 | $20,281.29 | $5,281.29 |
Setup: loan $15,000, APR 10.5%, term 48 months.
Line 1 — the monthly rate. 10.5% ÷ 12 = 0.875% a month, or 0.00875.
Line 2 — the number of payments. The term is already in months: 48 payments.
Line 3 — the growth factor. (1 + 0.00875)^48 = 1.51918.
Line 4 — the monthly payment. $15,000 × 0.00875 × 1.51918 ÷ (1.51918 − 1) = $131.25 × 1.51918 ÷ 0.51918 = $384.05 a month.
Line 5 — the total paid. $384.05 × 48 = $18,434.43.
Line 6 — the interest. $18,434.43 − $15,000 = $3,434.43.
Line 7 — the first payment. The first month’s interest is $15,000 × 0.00875 = $131.25, so the principal in the first payment is $384.05 − $131.25 = $252.80. The first year costs $1,424.66 of interest, and the last year costs $251.75, because the balance is nearly gone by then.
$10,000 loan: the payment is $256.03 a month, the total paid is $12,289.62, and the interest is $2,289.62. Borrowing a third less cuts the payment by $128.02 a month, because the payment scales with the loan at the same rate and term.
$25,000 loan: the payment is $640.08 a month, the total paid is $30,724.06, and the interest is $5,724.06. Borrowing $10,000 more costs $256.03 a month more, because the payment is the loan times the same factor.
APR 7%: the payment is $359.19 a month, the total paid is $17,241.30, and the interest is $2,241.30. A rate 3.5 points lower saves $24.86 a month and $1,193.13 of interest over 48 months.
APR 15%: the payment is $417.46 a month, the total paid is $20,038.14, and the interest is $5,038.14. A rate 4.5 points higher costs $33.41 a month more and $1,603.71 of interest over 48 months.
Term 24 months: the payment is $695.64 a month, the total paid is $16,695.37, and the interest is $1,695.37. Halving the term raises the payment by $311.59 a month but saves $1,739.06 of interest, because the loan is paid off in half the time.
Term 60 months: the payment is $322.41 a month, the total paid is $19,344.51, and the interest is $4,344.51. A longer term cuts the payment by $61.64 a month but costs $910.08 of extra interest, because the loan runs a year longer.
Term 72 months: the payment is $281.68 a month, the total paid is $20,281.29, and the interest is $5,281.29. Six years cuts the payment by $102.37 a month against 48 months but costs $1,846.86 of extra interest, because the balance stays high for longer.
Reverse — the loan a monthly payment affords: $300 a month affords a $11,717.20 loan, $400 a month affords $15,622.94, and $500 a month affords $19,528.67, all at 10.5% for 48 months. Work backwards from the payment when the budget is fixed: the loan is the payment times the same factor in reverse.
The model assumes a fixed APR for the whole term, with the same payment every month, and it assumes the loan is paid off in equal monthly payments with no extra payments, no fees and no origination charge. It assumes the APR is the rate that prices the loan, which is how most personal loans are quoted, and it leaves out the origination fee, which some lenders charge on top of the loan, and any late fees. It does not say whether a lender will approve you: the lender checks your credit, your income and your debts before it lends. Rounding convention: money is rounded to cents, and all figures are computed from unrounded values, rounded only for display.
| Output | Formula | What it means |
|---|---|---|
| Monthly payment | loan × r × (1+r)^n ÷ ((1+r)^n − 1) | $384.05 a month. |
| Total paid | payment × n | $18,434.43. |
| Total interest | total paid − loan | $3,434.43. |
| First payment interest | loan × r | $131.25. |
| First payment principal | payment − first interest | $252.80. |
| Interest in the first year | sum of the first 12 months’ interest | $1,424.66. |
| Interest in the last year | sum of the last 12 months’ interest | $251.75. |
| $10,000 loan | same model, $10,000 | $256.03/mo, $12,289.62 total, $2,289.62 interest. |
| $25,000 loan | same model, $25,000 | $640.08/mo, $30,724.06 total, $5,724.06 interest. |
| APR 7% | same model, 7% | $359.19/mo, $17,241.30 total, $2,241.30 interest. |
| APR 15% | same model, 15% | $417.46/mo, $20,038.14 total, $5,038.14 interest. |
| Term 24 months | same model, 24 months | $695.64/mo, $16,695.37 total, $1,695.37 interest. |
| Term 60 months | same model, 60 months | $322.41/mo, $19,344.51 total, $4,344.51 interest. |
| Term 72 months | same model, 72 months | $281.68/mo, $20,281.29 total, $5,281.29 interest. |
| Reverse: $300/mo affords | payment × ((1+r)^n − 1) ÷ (r × (1+r)^n) | $11,717.20. |
| Reverse: $400/mo affords | same inverse formula | $15,622.94. |
| Reverse: $500/mo affords | same inverse formula | $19,528.67. |
The math is exact for the numbers you enter: the payment follows the standard loan formula, the total paid is the payment times the months, the interest is the total minus the loan, and the first payment’s interest is the loan times the monthly rate. What the model cannot do is read your loan offer for you: check the APR on the offer, because a 7% offer and a 15% offer give very different payments, and check for an origination fee, which this calculator leaves out. It assumes a fixed APR, equal monthly payments, no extra payments, no fees and no late charges, and it leaves out the credit check: the lender checks your credit, your income and your debts before it lends. For the payment schedule, see amortization schedule calculator; for the home equity loan, see home equity loan calculator.
Bright Side Kit. "Personal Loan Calculator: Payment, Interest & Total 2026." https://brightoolbox.com/personal-loan-calculator/ Accessed October 25, 2026.Loan times the monthly rate factor. The monthly rate is 10.5% divided by 12, which is 0.875%, the payments are 48, and the payment is $15,000 times 0.00875 times (1.00875) to the power of 48, divided by (1.00875) to the power of 48 minus 1, which is $384.05 a month. The total paid is $384.05 times 48, which is $18,434.43.
$3,434.43 at 10.5% for 48 months. The total paid is $18,434.43, and the interest is $18,434.43 minus $15,000, which is $3,434.43. At 7% the interest is $2,241.30, and at 15% it is $5,038.14, so the rate matters more than the loan amount.
$384.05 a month at 10.5% for 48 months. At 7% it is $359.19 a month, and at 15% it is $417.46 a month. Over 24 months it is $695.64 a month, and over 72 months it is $281.68 a month.
$131.25 of the first $384.05. The first month’s interest is $15,000 times 0.875%, which is $131.25, so the principal in the first payment is $384.05 minus $131.25, which is $252.80. The first year costs $1,424.66 of interest, and the last year costs $251.75, because the balance is nearly gone by then.
For interest, yes; for the monthly budget, not always. A 24-month term costs $1,695.37 of interest against $3,434.43 at 48 months, so it saves $1,739.06, but the payment is $695.64 a month against $384.05. A 72-month term cuts the payment to $281.68 a month but costs $5,281.29 of interest. Pick the shortest term whose payment fits the budget.
$15,622.94 at 10.5% for 48 months. A $300 a month payment affords $11,717.20, and $500 a month affords $19,528.67, at the same rate and term. Work backwards from the payment when the budget is fixed.
Fees and the credit check. The $384.05 a month is the loan payment only: it leaves out any origination fee, which some lenders charge on top of the loan, and any late fees. A $15,000 loan costs $18,434.43 in loan payments over 48 months, and the fees are on top of that.
Usually the personal loan. A personal loan at 10.5% costs $3,434.43 of interest on $15,000 over 48 months, while a credit card at 22% would cost far more for the same balance, because the rate is higher and the minimum payment stretches the term. A personal loan also has a fixed end date, while a credit card does not.