CalculateItNow home

Loan Calculator

Work out the payment on any amortizing loan — personal, auto or business — with total interest, payoff date, extra payments, and a full amortization schedule.

Loan Calculator: with the default inputs, payment is $386.66.

$
%
years
months
Try an example
Payment
$386.66

Due each period at the frequency you picked (before any extra).

Total interest
$3,199
Total of all payments
$23,199
Payoff date
August 10, 2031
Number of payments
60
Time saved by extra payments
Interest saved by extra payments
$0
Assumptions
  • Interest is simple interest charged per payment period at the annual rate divided by the number of periods per year.
  • Payments are made at the end of each period; the first payment falls on the date you enter.
  • Extra payments go entirely to principal with no prepayment penalty.
Principal vs interest
  • Principal$20,00086%
  • Interest$3,19914%
Principal vs interest by year
$0$2k$4k12345Year
PrincipalInterest
Remaining balance
$0$5k$10k$15k12345Year
Balance
Amortization schedule (yearly)
YearPrincipalInterestTotal paidBalance
1$3,536$1,104$4,640$16,464
2$3,754$886$4,640$12,710
3$3,986$654$4,640$8,724
4$4,232$408$4,640$4,493
5$4,493$147$4,640$0
Amortization schedule (every payment)
#PaymentPrincipalInterestBalance
1$386.66$286.66$100.00$19,713.34
2$386.66$288.09$98.57$19,425.25
3$386.66$289.53$97.13$19,135.72
4$386.66$290.98$95.68$18,844.75
5$386.66$292.43$94.22$18,552.32
6$386.66$293.89$92.76$18,258.42
7$386.66$295.36$91.29$17,963.06
8$386.66$296.84$89.82$17,666.22
9$386.66$298.32$88.33$17,367.89
10$386.66$299.82$86.84$17,068.07
11$386.66$301.32$85.34$16,766.76
12$386.66$302.82$83.83$16,463.94
112 of 60
Math verified by automated testsUpdated 2026-09-082 sources cited

How this is worked out

The formula

A = P × [ r(1 + r)^n ] ÷ [ (1 + r)^n − 1 ]

P = loan amount
r = interest rate per period (annual rate ÷ payments per year)
n = total number of payments
Interest in a period = remaining balance × r; the rest of the payment reduces principal.

Open How it’s calculated above to see this worked through with your own numbers.

What you enter

Loan amount
The principal you borrow.in dollars · 0 or more · defaults to 20000
Interest rate
Annual rate on the note.a percentage · from 0 to 100 · defaults to 6
Term (years)
A number.from 0 to 50 · whole numbers only · defaults to 5
plus months
Add extra months to the term, e.g. 4 years + 6 months.from 0 to 11 · whole numbers only · defaults to 0
Payment frequency
Interest is charged per payment period at the annual rate ÷ periods per year.Monthly (12 / yr) · Every two weeks (26 / yr) · Weekly (52 / yr)
First payment date(under More options)
A calendar date.defaults to today
Extra payment(under More options)
Added to every payment and applied straight to principal.in dollars · 0 or more · defaults to 0

What you get back

Paymentmain answer
Due each period at the frequency you picked (before any extra).
Total interest
Total of all payments
Principal + interest.
Payoff date
Number of payments
Time saved by extra payments
Interest saved by extra payments

What this assumes

  • Interest is simple interest charged per payment period at the annual rate divided by the number of periods per year.
  • Payments are made at the end of each period; the first payment falls on the date you enter.
  • Extra payments go entirely to principal with no prepayment penalty.

About this calculator

Most loans you'll ever sign — personal loans, car loans, mortgages, many business loans — are amortizing: you make a level payment on a fixed schedule, each payment first covers the interest that accrued since the last one, and whatever is left chips away at the balance. Because the balance shrinks, the interest share falls every period and the principal share rises. This calculator gives you the payment, what the loan really costs, when it ends, and the full schedule showing where each dollar goes.

How to use it

Enter the amount, the annual rate, and the term. Split terms are fine — 4 years plus 6 months. The default is monthly payments; switch to every two weeks or weekly if that's how the lender bills you. Open More options to set the first payment date (so the payoff date is real) and to add an extra amount to every payment. Solve for works backwards: fix the payment you can afford and solve for the amount, rate or term.

Reading the results

  • Payment is the level amount due each period. It excludes any extra you add.
  • Total interest is the true price of borrowing. On a 5-year loan at 6%, it's about 16% of what you borrowed; at 12% it's more than double that.
  • Payoff date counts from the first payment date, so it lands on the last payment.
  • Time and interest saved appear when you add an extra payment. Because extra money goes straight to principal early on, when interest is highest, even small amounts punch above their weight.

Payment frequency

Paying biweekly or weekly doesn't change the interest rate, but it does mean the balance drops a little sooner each month, so total interest is slightly lower. The bigger win most people are thinking of — "biweekly mortgage" plans — comes from making half the monthly payment every two weeks, which adds up to 13 monthly payments a year; use the biweekly mortgage calculator for that comparison.

Things to check on the loan agreement

  • The rate here is the note rate. If the loan charges origination fees, the APR will be higher — the APR calculator converts fees into an effective rate.
  • Make sure extra payments are applied to principal, not held as a prepayment of the next installment.
  • Some loans (precomputed or "Rule of 78" loans) front-load interest so early payoff saves less than this schedule suggests. Simple-interest loans, the norm today, behave exactly like this.

Frequently asked questions

How is a loan payment calculated?

With the amortization formula A = P·r(1+r)ⁿ / ((1+r)ⁿ − 1), where P is the amount, r the per-period rate and n the number of payments. Each payment covers that period's interest first; the remainder reduces the balance.

What's the difference between interest rate and APR?

The interest rate sets the payment. APR also folds in upfront fees and points, spread over the term, so it's the better number for comparing lenders. With no fees, the two are equal.

Does paying biweekly save money?

A little, if the lender charges interest per period, because principal falls sooner. The big savings come from paying half the monthly amount every two weeks, which equals 13 monthly payments a year — check the biweekly mortgage calculator.

How do extra payments shorten a loan?

Extra money reduces the balance that future interest is computed on, so every following payment has a larger principal share. The loan ends early and you skip all the interest on the months you cut off.

Why is my first payment mostly interest?

Because the balance is at its highest. On $20,000 at 6%, the first month's interest is $100 of a $386.66 payment; by the last year it's a few dollars.

Put this calculator on your own site

A working loan, free for any site, with no ads and no sign-up. It resizes to fit wherever you paste it and updates itself as this page improves.

Paste this anywhere. It works on any site, carries no ads, never expires, and always shows the current version.

Loan Calculator by CalculateItNow

The page's own title. The clearest description of what the link leads to.

The credit line sits outside the widget on purpose, so it is a real link on your page rather than one buried in a frame. Please keep it — it is what pays for CalculateItNow staying free and ad-free. The script only resizes the widget to fit its contents; drop it and the widget still works.

Browse every calculator widget·How to add it to WordPress, Squarespace or Wix

The questions people ask next to a loan.

All finance calculators·Browse everything