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Free mortgage calculator spreadsheet

Type the price, down payment, rate and term. The sheet works out the monthly payment and builds the full amortization schedule, every payment split into interest and principal. Add an extra amount each month to see how much sooner the loan is paid off and how much interest you skip.

Pro Want to see your real monthly cost and exactly what extra payments would save? See Mortgage Calculator Pro →
Preview of the real sheet. Click the tabs underneath.Shaded cells are formulas
Calculatorrowsandcells.com
Monthly payment, full amortization schedule and extra payments.Free template
ItemYour numbersNotes
Home price ($)425,000The purchase price, or the home's value if you're refinancing
Down payment ($)85,000Cash you put down. 20% here, so no mortgage insurance
Loan amount$340,000.00Price minus down payment
Interest rate (% a year)6.5Type 6.5 for 6.5%. Use the rate, not the APR
Loan term (years)30Usually 30, 20, 15 or 10
First payment dateDec 1, 2026Usually the 1st of the second month after closing
Extra principal each month ($)200Optional. Type 0 for none
Down payment share20%Under 20% usually means mortgage insurance (PMI) on top
Number of payments360Term in years times 12
Monthly payment (principal and interest)$2,149.03Same as PMT(rate/12, payments, -loan). Taxes and insurance come on top
You pay each month with the extra$2,349.03Monthly payment plus your extra principal
First month: interest$1,841.67Most of the first payments go to interest
First month: principal$307.36The part of the payment that pays the loan down

What's inside

  • Monthly principal and interest payment from price, down payment, rate and term
  • A full amortization schedule for up to 30 years (360 payments): interest, principal and balance every month
  • An extra principal payment each month, applied straight to the balance
  • Side by side: payoff date, total interest and total paid with and without the extra
  • A year-by-year summary with interest, principal and balance at each year end
  • Works in Google Sheets and Excel, no add-ons or macros

How to use it

  1. Download your copy

    Click "Free download" to save the .xlsx file. It opens in Excel, or in Google Sheets: open a blank sheet (sheets.new) and choose File, then Import, then Upload. Your numbers stay private.

  2. Type your loan

    On the Calculator tab, type the home price, your down payment, the interest rate (6.5 for 6.5%) and the term in years. The loan amount and monthly payment fill in straight away.

  3. Set the first payment date

    Change the first payment date to the one on your closing papers or loan estimate. Every date on the schedule counts on from it.

  4. Try an extra payment

    Type an amount in Extra principal each month, or 0 for none. The Summary tab shows the new payoff date, how many payments you skip and the interest saved.

  5. Read the schedule

    The Schedule tab has one row per payment. Early on most of each payment is interest; by the end it's almost all principal. The By Year tab adds it up for each year of the loan.

  6. Check against your statement

    Once you have a real statement, compare its balance with the schedule. Small differences of a few dollars come from how your lender rounds or counts days.

Tips

Budget for the whole payment

This sheet works out principal and interest. Your real monthly bill usually adds property tax, homeowners insurance and sometimes PMI or HOA dues, which can add several hundred dollars.

Tell your lender where extra goes

When you pay extra, ask your servicer to put it toward principal, not toward next month's payment. Check the next statement to make sure it did.

Compare rates with the same loan

To compare two offers, save a copy of the sheet for each one. Keep the price and down payment the same and change only the rate, so the difference you see is the rate.

Check for prepayment rules

Most US home loans let you pay extra at any time, but some loans have prepayment penalties. Read your loan papers or ask your lender before you start. For big decisions like refinancing, talk to a housing counselor or financial advisor.

Questions

How is the monthly payment worked out?

With the standard loan formula: loan times monthly rate, divided by 1 minus (1 plus monthly rate) to the power of minus the number of payments. It gives the same number as Excel's and Google Sheets' PMT function.

Does this include taxes and insurance?

No, it shows principal and interest only, which is the part an amortization schedule covers. Add your property tax, homeowners insurance and any PMI or HOA fees on top to get the full monthly cost.

How do extra payments save money?

Interest each month is charged on the balance you still owe. An extra payment lowers that balance right away, so every later month charges less interest and more of your regular payment goes to principal. The loan ends early.

Can I use it for a 15-year mortgage?

Yes. Type 15 as the term. The schedule has room for 360 payments; rows after the last payment show zero.

Why doesn't it match my lender's numbers to the cent?

Lenders round each month's interest and may count days differently. The schedule rounds interest to the cent each month, so it usually lands within a few dollars of a real statement.

Can I use it for a car loan or personal loan?

Yes. Any fixed-rate loan with equal monthly payments works: type the amount as the home price, 0 as the down payment, and the rate and term from your loan.

Is this template free?

Yes. Download the .xlsx file and open it in Excel or Google Sheets. There's no sign-up and no email needed.

Pro version

Mortgage Calculator Pro

Type your loan once and see the full monthly cost, the payoff date and exactly what every extra payment saves you.

Every kind of extra payment

Add a bit extra every month from any start date, one bigger payment each year, and one-off lump sums like a bonus or tax refund, past or planned. The schedule counts them all.

See what your extras save

The Dashboard shows your payoff date with and without extras, the interest saved and how many years sooner you're done. A hidden second schedule keeps the comparison exact.

The whole monthly payment

Principal and interest plus property tax, insurance, HOA dues and PMI. A chart shows where your next payment goes.

Know when PMI ends

PMI stops when your balance reaches the share of the price you set (80% by default), so you can see how extra payments bring that date closer.

Compare loan offers

Type up to four Loan Estimates: rate, term, points, fees and credits. See the monthly payment, cash to close, total cost over the years you'll keep the loan and a points break-even.

Where you stand today

Balance, equity, interest paid so far and the next payment, all from today's date. Paid payments are marked on the schedule and the next one is highlighted.

FreePro
Monthly payment and 360-payment scheduleMonthly payment and 360-payment schedule
One extra amount every monthMonthly, yearly and one-off extra payments
Interest saved and payoff dateInterest, time and PMI saved, with a balance chart
·Property tax, insurance, HOA and PMI in every payment
·PMI end date, with and without extras
·Compare up to four loan offers with points and fees
·What-if ladder: $100 to $1,000 extra from today's balance
·Balance, equity and interest paid so far, as of today
Totals by loan yearTotals by calendar year, with a chart

$19 one-time

7 tabs: Start Here, Dashboard, Setup, Extra Payments, Schedule, By Year and Compare. You get two copies: one filled in with a sample loan so you can see it working, and a blank one ready for your own.

Buy now
  • Instant download after checkout
  • Works in Google Sheets and Excel
  • Yours to keep and reuse every year