Monthly Payment Calculator Payment, Amount, Rate & Term
Calculate your loan payment, maximum loan amount, required interest rate, or loan term. Supports monthly, bi-weekly, and weekly payment frequencies. Includes extra payment savings and a full amortisation schedule.
Country
Currency
📅
Loan Details
Solve For
€
Total amount borrowed.
%
Annual nominal interest rate.
mo
Number of payment periods.
€
Your known periodic payment amount.
freq
How often payments are made. Term adjusts to match.
Optional: Extra Payment & Loan Type
€
Additional principal paid each period. Shows time and interest saved.
type
For context labels only. Does not affect the calculation.
💰
Extra payment saves —
—
Payment
—
per period
Total Repaid
—
all payments
Total Interest
—
interest cost
Interest / Loan
—
interest as % of principal
Loan Amount
—
principal
Annual Rate
—
nominal
Term
—
periods
Payment Frequency
—
selected
Payment
—
per period
Period Interest (1st)
—
first payment
Period Principal (1st)
—
first payment
Total Interest
—
over term
Total Repaid
—
all payments
Interest % of Loan
—
interest ratio
Full Breakdown
Standard Repayment
Payment per period—
Total periods—
Total interest—
Total repaid—
With Extra Payment
Payment per period—
Total periods—
Total interest—
Interest saved—
Loan Balance Over Time
Standard balance
With extra payment
Payment at Different Rates
Rate (%)
Payment
Total Interest
Total Repaid
Payment at Different Terms
Term
Payment
Total Interest
Total Repaid
Amortisation: First 12 Periods
Period
Payment
Principal
Interest
Balance
Important: This calculator estimates loan payments using a standard amortisation formula. It does not account for fees, insurance, variable rates, balloon payments, or lender-specific terms. Results are estimates only.
✦ Cal, AI Explanation
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Cal
Your loan payment estimate is ready. Ask me about how the term affects total interest, what extra payments save, or how bi-weekly payments differ from monthly.
📅 Key Notes
Shorter term raises payment but reduces total interest significantly
Extra payments go entirely to principal, shortening the loan
Bi-weekly payments result in one extra monthly payment per year
Early periods are mostly interest; later periods mostly principal
Estimate only — does not include fees or variable rates
A standard fixed-rate loan uses the annuity formula to calculate the periodic payment. The formula is: payment = principal × (r × (1+r)^n) / ((1+r)^n − 1), where r is the periodic interest rate and n is the number of periods. The periodic rate is the annual rate divided by the number of periods per year.
Solve For
Inputs Required
Method
Payment
Amount, rate, term
Direct annuity formula
Loan amount
Payment, rate, term
PV = PMT × (1−(1+r)^−n)/r
Interest rate
Amount, payment, term
Newton-Raphson iteration
Term
Amount, payment, rate
Logarithmic formula
How payment frequency affects the loan
Bi-weekly payments (every two weeks) produce 26 payments per year instead of 24. This is equivalent to making 13 monthly payments per year instead of 12, which reduces the principal faster and shortens the loan. Weekly payments accelerate repayment further. The interest rate is divided by the number of periods per year (12 for monthly, 26 for bi-weekly, 52 for weekly) to get the periodic rate.
How extra payments work
An extra payment goes entirely to reducing the principal balance because the scheduled payment has already covered that period's interest. A smaller principal means less interest accrues in every subsequent period, which reduces both the total interest paid and the number of periods required to pay off the loan. Even a small extra payment consistently applied can save a meaningful amount over a long loan term.
Frequently Asked Questions
What is the difference between monthly and bi-weekly payments?+
Monthly payments are made 12 times per year. Bi-weekly payments are made every two weeks, which results in 26 payments per year instead of 24. Because two extra half-payments are made annually, the principal reduces faster and the loan is paid off sooner, saving interest. The bi-weekly payment amount is approximately half the monthly payment.
Do extra payments reduce the term or the payment?+
For a standard fixed-rate loan, extra payments reduce the principal balance, which shortens the remaining term rather than reducing the scheduled payment amount. Fewer periods are needed to clear the balance because the outstanding principal is lower at each step. Some lenders allow you to choose between reducing the term and reducing the payment, but this calculator models the more common term reduction.
Why does the first payment include so much interest?+
Interest is calculated on the outstanding balance at each period. In the first period the full principal is outstanding, so the interest charge is at its highest. Each subsequent payment reduces the principal slightly, so less interest accrues the following period. This means early payments go mostly to interest and later payments go mostly to principal. This is called front-loaded amortisation.
How is the loan amount calculated from a known payment?+
If you know the payment, rate, and term, the maximum loan amount (present value) is: PV = PMT × (1 − (1+r)^−n) / r, where r is the periodic rate and n is the number of periods. This is the standard present value of an annuity formula and is used in the Loan Amount solve mode.
How is the interest rate calculated from a known payment?+
When the payment, loan amount, and term are all known, the interest rate must be found iteratively because there is no closed-form algebraic solution. This calculator uses the Newton-Raphson method, which starts from an initial guess and refines it until the payment produced by the guessed rate matches the known payment to within a very small tolerance.
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