OpusDesk Hub What this tool does
Estimate a fixed-rate loan’s monthly payment and amortization. Let P be principal, r be annual percentage rate ÷ 100 ÷ 12 and n = years × 12. Monthly payment = P·r·(1+r)^n ÷ ((1+r)^n−1); at zero interest it is P/n. The schedule applies monthly interest to the remaining balance and adds the entered extra payment to principal, rounding balances to cents.
How to use Loan Calculator
- Prepare the input. Enter principal, annual rate, years and optional monthly extra payment.
- Run or configure the tool. Select Calculate and inspect the payment and total interest.
- Check and use the output. Expand the schedule if needed and compare it with the lender’s documents.
How this tool works
Let P be principal, r be annual percentage rate ÷ 100 ÷ 12 and n = years × 12. Monthly payment = P·r·(1+r)^n ÷ ((1+r)^n−1); at zero interest it is P/n. The schedule applies monthly interest to the remaining balance and adds the entered extra payment to principal, rounding balances to cents.
Worked example
Input: Principal 1,200; annual interest 0%; term 1 year; extra payment 0
Output: Monthly payment $100.00; interest $0.00; total cost $1,200.00.
Limits, assumptions and interpretation
Enter a positive principal and term, non-negative annual interest and a non-negative extra payment. Use a term that represents whole monthly payments.
- Rates are your inputs, not live quotations or APR calculations. Fees, penalties, insurance and taxes are not included.
- Changing/variable rates, daily interest conventions, odd first periods and lender-specific rounding are not modeled.
- This is a planning estimate, not a loan offer or personal financial advice; compare with the lender’s actual schedule.
Supported inputs and limits
- Principal 1,200; annual interest 0%; term 1 year; extra payment 0
- Enter a positive principal and term, non-negative annual interest and a non-negative extra payment. Use a term that represents whole monthly payments.
- Rates are your inputs, not live quotations or APR calculations. Fees, penalties, insurance and taxes are not included.
- Changing/variable rates, daily interest conventions, odd first periods and lender-specific rounding are not modeled.
- This is a planning estimate, not a loan offer or personal financial advice; compare with the lender’s actual schedule.
Sources and specifications
Planning assumptions
Rates are your inputs, not live quotations. A fixed-rate amortization estimate excludes fees, taxes, insurance, penalties and changing interest unless explicitly entered. Confirm the lender's actual schedule.
CFPB loan estimate explanationFrequently asked questions
What does this tool actually do?
Let P be principal, r be annual percentage rate ÷ 100 ÷ 12 and n = years × 12. Monthly payment = P·r·(1+r)^n ÷ ((1+r)^n−1); at zero interest it is P/n. The schedule applies monthly interest to the remaining balance and adds the entered extra payment to principal, rounding balances to cents.
What should I check before using the result?
Enter a positive principal and term, non-negative annual interest and a non-negative extra payment. Use a term that represents whole monthly payments. Rates are your inputs, not live quotations or APR calculations. Fees, penalties, insurance and taxes are not included. Changing/variable rates, daily interest conventions, odd first periods and lender-specific rounding are not modeled. This is a planning estimate, not a loan offer or personal financial advice; compare with the lender’s actual schedule.
Is information sent to a server?
Tool inputs are processed in this browser. This product does not use analytics or send your input to an external API. Clicking an external website link still visits that website.