Loan Repayment Calculator
A free loan repayment calculator for monthly payments, total interest, and the full cost of borrowing on any fixed-rate loan — mortgage, car, student or personal.
Monthly Payment
$1,073.64
Total Paid
$386,511.57
Total Interest
$186,511.57
48.3% of total paid
Cost Breakdown
How to use this calculator
- Enter the total loan amount (the principal you are borrowing).
- Enter the annual interest rate quoted by your lender.
- Enter the loan term in years (e.g. 30 for a 30-year mortgage, 5 for a car loan).
- Results update instantly — compare different scenarios by adjusting the inputs.
Popular loan repayment scenarios
- 30-year $300K mortgage at 5%
- 30-year $200K mortgage at 6%
- 30-year $500K mortgage at 7%
- 25-year $400K mortgage at 6%
- 15-year $150K mortgage at 5%
- 30-year $250K mortgage at 6.5%
- 30-year $600K mortgage at 6%
- 5-year $30K car loan at 5%
- 4-year $25K car loan at 6%
- 3-year $20K personal loan at 8%
- 5-year $10K personal loan at 10%
- 15-year $100K home-equity loan at 7%
How the loan repayment calculator works: amortization explained
When you borrow at a fixed rate, the monthly payment is calculated so principal plus interest is paid off in equal installments over the term (amortization). The formula uses principal P, monthly rate r (annual ÷ 12), and number of payments n.
Early payments are mostly interest; over time more goes to principal. Extra payments early on save a lot of total interest because they avoid years of compounding interest on that balance.
Shortening the term (e.g. 15 vs 30 years) raises the payment but often cuts total interest sharply. Use the calculator to model rate and term changes before you sign.
Comparing two offers is where a loan repayment calculator earns its keep, because a rate gap that sounds trivial is easier to judge in money. Take a $25,000 car loan over five years: at 6% the payment is $483 a month and the interest adds up to $3,999, while at 7% it is $495 and $4,702. The monthly difference is about $12 — small enough to shrug at in the showroom, and $703 by the time the loan ends. Enter each quote with the same amount and term so you are comparing the loans rather than the assumptions.
The same arithmetic shows why paying a little extra early is so effective. A $300,000 mortgage over 30 years at 5% costs $1,610 a month and $279,767 in interest if you never deviate from the schedule. Round the payment up by $100 and the loan clears about 3 years and 8 months early; make it $200 and you finish roughly 6 years 5 months early, because every extra dollar removes all the future interest that dollar would have carried. Paying half the payment every two weeks works through the same mechanism: it quietly adds one extra monthly payment a year.
Two things this calculator deliberately leaves out. It uses the interest rate, not the APR, so origination fees, points and broker charges are not in the monthly figure — compare APRs separately when lenders quote them. And it models the loan alone: a mortgage payment usually also carries property tax, home insurance and possibly PMI, which the dedicated mortgage calculator adds on top. For a fixed-rate personal, car or student loan with no fees rolled in, the number here is the whole payment.
Key formulas (reference)
Monthly payment (fixed rate, monthly compounding): M = P × [r(1+r)^n] / [(1+r)^n − 1], where P = principal, r = annual rate / 12, n = years × 12. If r = 0, M = P / n.
In-depth guides
- How Mortgage Payments Are Calculated: Principal, Interest, Tax and Insurance
The amortisation formula behind every fixed-rate mortgage, a full worked example, why early payments are mostly interest, and what PMI and escrow add.
- Fixed vs Adjustable-Rate Mortgages: How ARMs Work and When They Make Sense
How an ARM’s fixed period, index, margin and caps work, a side-by-side example against a fixed loan, and the questions to ask before choosing one.
- Compound Interest vs Simple Interest: Examples, APY and the Rule of 72
What compounding really adds, how frequency and APY compare, why the Rule of 72 works, and how the same maths makes credit-card debt so expensive.
Related tools
These free tools pair well with this page — open them in a new tab to finish your workflow.
Frequently Asked Questions
How is the monthly payment calculated?
Monthly payment = P × [r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate / 12), and n is the total number of payments. This is the standard amortization formula for fixed-rate loans.
What is amortization?
Amortization is the process of paying off a loan through regular scheduled payments. Early payments are mostly interest; over time, more of each payment goes toward the principal. An amortization schedule shows the exact split for every payment.
What happens if I make extra payments?
Extra payments reduce the outstanding principal, which in turn reduces the total interest paid over the life of the loan and can shorten the repayment term significantly. Even one extra payment per year can save years off a 30-year mortgage.
What is an APR vs an interest rate?
The interest rate is the cost of borrowing the principal. APR (Annual Percentage Rate) includes the interest rate plus additional costs like origination fees, points, and other charges. APR is a more complete measure of the true cost of the loan.
Does it work for student loans?
Yes, for a fixed-rate student loan in normal repayment: enter the balance, the rate and the years remaining. It does not model a grace period, interest that capitalises before repayment starts, or income-driven plans where the payment is set by your earnings rather than the balance. For federal loans on such a plan, check the servicer's own estimate.
Does this loan repayment calculator include fees or insurance?
No. It works from the interest rate, the amount and the term, so origination fees, points and insurance are not included. That matches a straightforward personal, car or student loan. For a home purchase, use the mortgage calculator instead — it adds property tax, home insurance, PMI and HOA on top of principal and interest.
Can I model biweekly payments?
Not directly, but the effect is easy to reproduce: paying half the monthly amount every two weeks results in 26 half-payments, which is one extra monthly payment a year. Divide that extra payment by 12 and add it as a small extra monthly amount to see the same shortened term and interest saving.
What is a balloon payment?
A balloon payment is a large lump-sum payment due at the end of the loan term. Balloon mortgages typically have lower monthly payments for an initial period, then the remaining balance is due all at once. This tool calculates standard fully-amortizing loans without balloon payments.
What is the difference between principal and interest?
Principal is the original loan amount that you borrowed. Interest is the fee charged by the lender for the use of that money. Your monthly payment covers both — early in the loan, most goes to interest; as the principal decreases, more of each payment goes to principal.