See what your loan really costs.
Your monthly payment, the full amortization schedule, and exactly how much paying extra saves you in interest and time. For mortgages, car loans and more. No macros.
✓ One-off payment ✓ Instant download ✓ Excel for Windows & Mac
| Normal | With extras | |
|---|---|---|
| Monthly payment | $2,212.24 | $2,212.24 + $200 |
| Number of payments | 360 | 278 |
| Paid off | Sep 2056 | Nov 2049 |
| Total interest | $446,406 | $323,195 |
Most people never see the full cost of their loan
The interest adds up
On a 30-year mortgage you can pay more in interest than you borrowed.
“Is paying extra worth it?”
An extra $200 a month sounds small. It’s hard to picture what it saves.
Confusing lender tables
Amortization schedules from lenders are hard to read and impossible to play with.
Type your loan. See every payment.
Type your loan
The amount, interest rate, term and when payments start.
Add extras
An extra amount every month, and/or a one-off lump sum, like a bonus or tax refund.
See the savings
Interest saved, time saved, the full schedule, and charts of your balance falling.
Every payment, until it’s paid off
The schedule shows the interest, principal, extra and balance for every payment, up to 40 years. The lump-sum month is highlighted, and there’s a column with the balance you’d have without extras.
- Up to 480 payments
- Extra monthly and one-off payments
- Year-by-year totals
| # | Date | Interest | Principal | Extra | Balance |
|---|---|---|---|---|---|
| 1 | Oct 2026 | $1,895.83 | $316.41 | $200.00 | $349,483.59 |
| 2 | Nov 2026 | $1,893.04 | $319.20 | $200.00 | $348,964.39 |
| 3 | Dec 2026 | $1,890.22 | $322.02 | $200.00 | $348,442.37 |
| … | |||||
| 24 | Sep 2028 | $1,827.51 | $384.73 | $5,200.00 | $331,802.64 |
See what paying extra saves
Add $200 a month and a $5,000 lump sum to a $350,000 mortgage and you save $123,211 in interest and pay it off 6 years 10 months sooner. Change the numbers and see your own.
- Interest saved
- Time saved and new payoff date
- Balance chart, with and without extras
| Normal | With extras | |
|---|---|---|
| Monthly payment | $2,212.24 | $2,212.24 + $200 |
| Number of payments | 360 | 278 |
| Paid off | Sep 2056 | Nov 2049 |
| Total interest | $446,406 | $323,195 |
Compare three loans side by side
15 years or 30? A lower rate? Paying extra? Put three loans next to each other and see the payment, months and total interest for each.
- Payment and months to pay off
- Total interest for each
- The cheapest option highlighted
| 30 years | 15 years | 30 yr + $300 | |
|---|---|---|---|
| Rate | 6.500% | 5.900% | 6.500% |
| Monthly payment | $2,212 | $2,935 | $2,512 |
| Months to pay off | 360 | 180 | 261 |
| Total interest | $446,406 | $178,232 | $303,411 |
For anyone with a loan, or thinking about one
Homeowners
See your mortgage schedule and what overpaying would save.
Home buyers
Compare terms and rates before you choose a mortgage.
Car & student loans
Any fixed-rate loan from 1 to 40 years.
Everything you get
- Monthly payment with PMT
- Property tax and insurance for total monthly cost
- Full amortization schedule, up to 40 years
- Extra every month and a one-off lump sum
- Interest saved, time saved and new payoff date
- Year-by-year interest and principal
- Balance chart, with and without extras
- Compare 3 loans side by side
- Works for mortgages, car loans, student loans and personal loans
One-off payment. Yours to keep.
Get instant access $7.99Secure checkout by Payhip · Card or PayPal
Download link emailed straight away
Hi, I’m Lee
I run Sheet Leveller on YouTube, where I make quick, no-nonsense Excel tutorials.
This calculator uses Excel’s PMT and FV functions from my tutorials, so every number is worked out, not guessed.
Questions
Does it work for adjustable-rate mortgages?
It’s built for fixed rates. For an ARM, you can use it for the fixed period.
Why might my lender’s numbers differ?
Lenders round interest in slightly different ways, so the last few cents can differ.
Can I use it outside the US?
Yes. It works for any currency. Just type your numbers.
Is this financial advice?
No. It’s a calculator to help you understand your loan. Talk to your lender or an adviser before making big decisions.
Does it use macros?
No. It’s a normal .xlsx file, so there are no security warnings and nothing to enable.
Which versions of Excel does it work with?
Microsoft 365, Excel 2010 or later on Windows, and Excel for Mac. It’s built for Microsoft Excel.
Is this a subscription?
No. You pay once and the file is yours to keep.
Know your loan inside out.
Your payment, every payment, and what paying extra saves.
Get the calculator $7.99Not ready yet? Try the free Simple Loan Calculator.