Installment math · Amortized, not estimated
Installment loan calculator
Pick an amount and a term: the calculator prices the installment market's common sizes at the 36% benchmark APR and shows the monthly payment, the total interest and what each credit tier changes. The math is the standard amortization formula — no email, no soft pull, no invented quotes.
Precomputed rows
Every common size at the 36% benchmark
| Amount | 12 mo payment | 18 mo payment | 24 mo payment | Total interest, 24 mo |
|---|---|---|---|---|
| $1,500 | $150.69 | $109.06 | $88.57 | $625.71 |
| $2,000 | $200.92 | $145.42 | $118.09 | $834.28 |
| $3,000 | $301.39 | $218.13 | $177.14 | $1,251.41 |
| $4,000 | $401.85 | $290.83 | $236.19 | $1,668.55 |
| $5,000 | $502.31 | $363.54 | $295.24 | $2,085.69 |
Fixed 36% APR, standard amortization — the ceiling benchmark this market quotes where no lower state schedule applies. Amount pages carry each state's lawful structure; the lender's disclosed APR and total of payments are the binding figures.
What the credit tier changes
Same $3,000 over 24 months — the only variable is the rate your profile commands:
| Credit tier | APR | Monthly payment | Total interest |
|---|---|---|---|
| Strong credit | 8% | $135.68 | $256.36 |
| Average credit | 15% | $145.46 | $491.04 |
| Damaged credit | 30% | $167.74 | $1,025.72 |
The gap between the top and bottom tier on this one loan is $769.36 — more than half the amount borrowed. Where your quotes land in the bottom tier, shrinking the amount or the term, or a credit-union PAL at the 28% federal cap, usually beats stretching expensive months.
Questions people ask about installment payments
How is an installment loan payment calculated?
With the standard amortization formula: payment = P × r ÷ (1 − (1 + r)^−n), where P is the amount borrowed, r is the monthly rate (APR ÷ 12) and n is the number of monthly payments. A $3,000 loan at 36% APR over 24 months works out to $3,000 × 0.03 ÷ (1 − 1.03^−24) ≈ $177.14 a month — 24 payments totaling $4,251.36. The calculator above runs this math for every size and term in this market.
What APR do installment loans charge?
It depends on the license and your credit. State-licensed installment lenders price against each state's small-loan caps; where no payday-style fee schedule exists, 36% APR is the common benchmark ceiling this market quotes — and the figure our tables use. Strong credit can land in the single digits; damaged credit on unlicensed or tribal products can face triple digits. The lender's written APR and total of payments are the only binding numbers.
Can I pay off an installment loan early?
With a compliant licensed loan, yes, without a penalty — prepayment penalties are banned for most consumer installment credit, and the interest you avoid simply never accrues. Confirm the line in your agreement before signing: any lender charging an early-payoff fee has said so in the contract, and that clause is a reason to walk. Paying early is the single cheapest way to cut this product's cost.
Is an installment loan cheaper than a payday loan?
Per dollar and per month, almost always. A $300 installment loan at the 36% benchmark over 3 months costs about $34 in interest; a storefront payday fee for the same $300 runs $45–$75 for two weeks in the states that allow it — and renewal doubles it. The installment product buys the same cash at a fraction of the annualized cost, which is why it is the licensed route in states that price payday out of the market.
How much installment loan can I get?
Online installment lenders typically offer $1,500–$5,000, sized against your income and credit profile; federal credit-union PALs run $200–$2,000 under a 28% APR ceiling. Amount caps are also a state matter — the state guides linked from the table above list each jurisdiction's ceiling and the regulator to check it with.
LendMap USA is an information platform, not a lender: this calculator computes the arithmetic of published benchmarks — it is not an offer of credit.