Loans
Loan Calculator
Work out the true cost of any fixed-rate loan — personal, auto, student, or business. Enter the amount, rate, and term to see your monthly payment, total interest, and a year-by-year balance. Add an extra monthly payment to see how much faster (and cheaper) the loan disappears.
Formula shown below · Tested against worked examplesHow we verify
Applied straight to principal every month.
Monthly payment: $415.17
Monthly payment
$415.17
- Total interest
- $4,910
- Total paid
- $24,910
- Paid off in
- 5 years
Balance by year
| Year | Principal paid | Interest paid | Remaining balance |
|---|---|---|---|
| 1 | $3,317 | $1,665 | $16,683 |
| 2 | $3,628 | $1,354 | $13,056 |
| 3 | $3,968 | $1,014 | $9,088 |
| 4 | $4,340 | $642 | $4,747 |
| 5 | $4,747 | $235 | $0 |
Compare scenariosTry three values of one input
| Loan amount | |||
|---|---|---|---|
| Monthly payment | $373.65 | $415.17+$41.52 | $456.68+$83.03 |
| Total interest | $4,419 | $4,910+$491 | $5,401+$982 |
| Total paid | $22,419 | $24,910+$2,491 | $27,401+$4,982 |
Every other input stays at the value you set above — currently $20,000 for loan amount. Differences are measured against the first column.
Saved scenariosSave this calculation
Saved in this browser only — no account, and nothing is sent to us. Clearing your browser data deletes them.
How this calculator works
Payments come from the standard fully-amortizing formula. The schedule posts interest in exact cents each month; the final payment self-adjusts so principal sums exactly to the amount borrowed.
Extra payments are applied entirely to principal in the same month. Interest savings are the difference between your schedule and the no-extra baseline, computed with identical rounding.
Educational estimates only — actual offers depend on your credit profile and lender fees.
Formula
M = P × i(1+i)ⁿ ÷ ((1+i)ⁿ − 1)
Total interest = (M × n) − P- M
- Monthly payment
- P
- Amount borrowed
- i
- Monthly rate: annual rate ÷ 12
- n
- Number of monthly payments
The same amortising formula every fixed-rate instalment loan uses. At a zero rate it reduces to P ÷ n. Interest accrues on the outstanding balance, so any extra payment reduces every future interest charge.
What this assumes
- A fixed rate and equal monthly payments for the whole term.
- Interest accrues on the outstanding balance, so it falls as the balance does — this is not a flat or precomputed-interest loan.
- No origination fee, insurance or late charges. A quoted APR that includes fees will be higher than the rate entered here.
What changes this number
- Term length
- Stretching the term always lowers the payment and raises the total interest. It is the lever lenders reach for, and the one worth resisting.
- Interest rate
- Dominates total cost on longer terms and matters less on short ones, because there is less time for interest to compound.
- Extra payments
- Anything above the required payment reduces the balance every future interest charge is calculated on, so early extra payments are worth far more than late ones.
A worked example
Take the used car: $18k at 7.5% for 60 months scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.
What you enter
- Loan amount
- $18,000
- Interest rate (APR)
- 7.5%
- Term (months)
- 60 months
What it returns
- Monthly payment
- $360.68
- Total interest
- $3,641
- Total paid
- $21,641
- Paid off in
- 5 years
Sources
This calculator uses no external data — the result follows entirely from the formula above and the values you enter, so there is nothing to cite beyond the arithmetic.
Calculator last reviewed August 8, 2026. How we verify
Try an example
Frequently asked questions
How is a loan payment calculated?
Fixed-rate loans use the amortization formula M = P × r(1+r)^n / ((1+r)^n − 1), where P is the amount borrowed, r the monthly rate (APR ÷ 12), and n the number of months. Early payments are mostly interest; the mix shifts toward principal as the balance falls.
Do extra payments really make a difference?
Yes — every extra dollar goes straight to principal, which shrinks the balance that next month's interest is charged on. On a $20,000 loan at 9% over 60 months, an extra $100/month saves roughly $900 in interest and pays the loan off about a year early. Run your own numbers above.
What's the difference between interest rate and APR?
The interest rate is the cost of borrowing the principal; APR adds mandatory fees (like origination charges) and expresses the total as a yearly rate, which makes it the better number for comparing offers. For a no-fee loan the two are identical.
Is it better to choose a shorter term?
A shorter term raises the monthly payment but cuts total interest substantially, and lenders often price shorter terms at lower rates. Choose the shortest term whose payment fits comfortably in your budget — or keep the longer term and make extra payments for the same effect with more flexibility.
What is the monthly payment on a $25,000 personal loan?
At 9% over five years the payment is $518.96 a month, with $6,138 of total interest — so you repay about $31,138 in all. Shortening the term raises the payment and cuts the interest sharply; lengthening it does the reverse.
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Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.