| Year | Principal paid | Interest paid | Remaining balance |
|---|
About Signet
Signet calculates your monthly payment, total interest, and full amortization schedule for a loan or mortgage, updating live as you adjust the numbers. Nothing you enter is uploaded or sent to a server.
Features
- General loan mode or mortgage mode with home price and down payment
- Live monthly payment and total interest calculation
- Extra monthly payment modeling, with time and interest saved
- Year-by-year amortization schedule
- Works for auto loans, personal loans, student loans, or a mortgage
- Runs entirely in your browser — nothing is uploaded
How to use it
- Choose General Loan or Mortgage from the tabs above.
- For a mortgage, enter the home price and down payment; the loan amount fills in automatically.
- Enter the interest rate and loan term.
- Optionally add an extra monthly payment to see how much time and interest it saves.
- Tap "Show yearly schedule" for a year-by-year breakdown of principal and interest.
Frequently asked questions
How is the monthly payment calculated?
It uses the standard amortization formula, based on the loan amount, monthly interest rate, and number of payments, so principal and interest are paid off evenly over the loan term.
Does this include taxes, insurance, or PMI?
No — this covers principal and interest only. Property taxes, homeowners insurance, PMI, and HOA fees vary too much by location and lender to estimate accurately here, so you'll want to add those separately.
How does the extra payment field work?
Any amount you add there is applied directly to the principal each month, which shortens the loan term and reduces total interest. The "interest saved" and "time saved" figures compare against paying with no extra amount.
Is my financial information sent anywhere?
No. All calculations happen locally in your browser using plain JavaScript — nothing is uploaded to a server.