Calculator Servicescalculatorservices.com
Financial

Loan Repayment Calculator

Plan your loan repayment schedule. Free online Loan Repayment Calculator for financial — instant, accurate results, mobile-friendly, no signup needed.

Monthly payment = P·r/(1 − (1+r)^−n).
Monthly payment
$289.99
Total interest
$2,399.52

Derivation

  1. ├── 01GivenP = 15000, r = 6, n = 5
  2. ├── 02FormulaMonthly payment: Zs(t,a / 100 / 12,12 × n)
  3. ├── 03SubstituteZs(t,a / 100 / 12,12 × 5)
  4. ├── 04Compute Monthly payment$289.99
  5. ├── 05FormulaTotal interest: Zs(t,a / 100 / 12,12 × n) × n × 12-t
  6. ├── 06SubstituteZs(t,a / 100 / 12,12 × 5) × 5 × 12-t
  7. └── 07Compute Total interest$2,399.52
Did you know?

Every calculator here runs 100% in your browser — nothing is sent to a server or stored in a database.

§01What is

Understanding the Loan Repayment Calculator

The Loan Repayment Calculator computes Monthly payment from 3 inputs: loan ($), rate (%), years. Plan your loan repayment schedule.

Quick calculators for the math that shouldn’t need a notepad — instant, accurate, private to your browser. The Loan Repayment Calculator sits in that toolkit — it plan your loan repayment schedule. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.

§02The Formula

How it’s calculated

Monthly payment = Zs(t,a / 100 / 12,12 × n) | Total interest = Zs(t,a / 100 / 12,12 × n) × n × 12-t

Where

P
Loan ($)
r
Rate (%)
n
Years
Monthly payment
Output value
Total interest
Output value
§03Practical Example

Step-by-step walkthrough

Scenario

Apply the formula to a realistic set of inputs: Loan ($) = 15000, Rate (%) = 6, Years = 5.

  1. 01Start by noting the input — Loan ($): 15000.
  2. 02Start by noting the input — Rate (%): 6.
  3. 03Start by noting the input — Years: 5.
  4. 04Substitute these values into the formula: Monthly payment = Zs(t,a / 100 / 12,12 × n) | Total interest = Zs(t,a / 100 / 12,12 × n) × n × 12-t
  5. 05Compute Monthly payment: the calculator returns 289.992.
  6. 06Compute Total interest: the calculator returns 2399.52.
  7. 07Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04Variants

Common Loan Repayment Problems

The formula gets rearranged depending on which variable you need. Here are the patterns you’ll run into in the real world — find the one that matches your problem and follow the worked steps.

01 · PATTERN

Loan ($) halved

P = 7500 (from 15000)

Keep every other input at its default and halve the loan ($). See how monthly payment responds.

  1. 01New Loan ($): 7500
  2. 02Baseline Monthly payment: 289.992
  3. 03New Monthly payment: 144.996
  4. 04Monthly payment decreases by 50% → use this sensitivity to plan for real-world variation.
02 · PATTERN

Loan ($) doubled

P = 30000 (from 15000)

Keep every other input at its default and double the loan ($). See how monthly payment responds.

  1. 01New Loan ($): 30000
  2. 02Baseline Monthly payment: 289.992
  3. 03New Monthly payment: 579.984
  4. 04Monthly payment increases by 100% → use this sensitivity to plan for real-world variation.
03 · PATTERN

Rate (%) halved

r = 3 (from 6)

Keep every other input at its default and halve the rate (%). See how monthly payment responds.

  1. 01New Rate (%): 3
  2. 02Baseline Monthly payment: 289.992
  3. 03New Monthly payment: 269.53
  4. 04Monthly payment decreases by 7.1% → use this sensitivity to plan for real-world variation.
04 · PATTERN

Rate (%) doubled

r = 12 (from 6)

Keep every other input at its default and double the rate (%). See how monthly payment responds.

  1. 01New Rate (%): 12
  2. 02Baseline Monthly payment: 289.992
  3. 03New Monthly payment: 333.667
  4. 04Monthly payment increases by 15.1% → use this sensitivity to plan for real-world variation.
§05FAQ

Frequently asked questions

Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
Your feedback

How useful was this calculator?

Your ratings stay in your browser — they help us learn which tools people actually rely on.

Rate it
Was this helpful?