What is Payment Calculator?
A payment calculator solves for the regular installment required to extinguish a debt balance given a fixed APR and specified number of periods.
How to Use This Calculator
- Input your total balance.
- Specify the loan APR.
- Choose payment term in months.
- The monthly payment updates in real-time.
The Mathematical Formula & Variables
PMT = P * [r(1+r)^n] / [(1+r)^n - 1]
Variables Definition
| Symbol / Variable | Name | Description |
|---|---|---|
PMT |
Payment | Equal monthly installment. |
P |
Loan Balance | Amount borrowed. |
r |
Monthly Rate | APR / 12. |
n |
Number of Months | Loan term in months. |
Step-by-Step Worked Example
Scenario: $10,000 personal installment loan for 36 months at 9.5% APR.
- Monthly rate r = 0.095 / 12 = 0.0079167.
- (1 + r)^36 = (1.0079167)^36 = 1.3281.
- Numerator = 0.0079167 * 1.3281 = 0.010515.
- Denominator = 1.3281 - 1 = 0.3281.
- PMT = $10,000 * (0.010515 / 0.3281) = $320.48.
Result: Monthly installment is $320.48. Total interest paid over 3 years is $1,537.28.
Frequently Asked Questions
How does payment frequency affect total interest?
Switching to bi-weekly payments results in 26 half-payments per year (equivalent to 13 full payments), shaving months off your repayment term.