Amortization Schedule Calculator
Enter the values the amortization schedule form asks for and the result is computed here, in the page, with no sign-up and no upload. Change one field at a time to see how sensitive the amortization schedule figure is to that assumption.
Loan Information
Extra Payment Options
Early Repayment Plan
Tax Information
Loan Comparison
Loan 1
Loan 2
Current Loan Information
New Loan Information
The formula, worked through
Interestₖ = Balanceₖ₋₁ × r; Principalₖ = M − Interestₖ
M = fixed monthly payment · r = monthly rate · k = payment number
- A $200,000 loan at 6% for 30 years pays $1,199.10 per month.
- Month 1 interest: 200,000 × 0.005 = $1,000.00, so only $199.10 reduces the balance.
- Month 2 interest: 199,800.90 × 0.005 ≈ $999.00 — the principal share rises by about $0.90 and compounding continues.
- Roughly 80% of the first year's payment is interest; the crossover to majority-principal payments happens around year 19.
- Balance
- $200,000
- Rate
- 6%
- Term
- 30 years
Result $1,199.10/month · first-month interest $1,000.00 · first-month principal $199.10
How to Master Your Loan Payoff Timeline With a Smarter Amortization Schedule Calculator
Let’s be real: few things are as frustrating as signing a loan agreement and realizing months later that you still don’t know exactly where your money is going. You see the monthly payment leave your account, but how much of it is actually chipping away at what you borrowed? And how much is just vanishing into interest?
That’s where an amortization schedule calculator changes everything. Unlike a simple loan calculator that only tells you your monthly payment, this tool creates a complete roadmap of your debt—showing every single payment from start to finish, how much goes to principal versus interest, and exactly when you’ll be free and clear. And the version I’m sharing with you today does all of that without you ever uploading a single file to a server.
Why I stopped using bank calculators (and you should too)
Most online loan tools force you to enter your personal financial details into some unknown database. If you’ve ever hesitated before typing your real loan balance into a random website, you’re not alone. I’ve been there—staring at an input field, wondering if my data would end up sold to some lender.
The amortization calculator I rely on at heycalc.org solves this the right way. Everything runs locally in your browser. Think of it like a spreadsheet on your own computer: your loan amount, interest rate, even your tax rate—none of it ever touches an external server. That means you can use it for your primary mortgage, a business loan with confidential terms, or even help a family member compare refinance offers without worrying about privacy leaks.
See the real cost of your loan before you sign anything
Let me walk you through how I actually use this tool when I’m evaluating a loan. Say you’re looking at a $250,000 mortgage at 4.5% for 30 years. Most basic calculators will tell you the monthly payment is around $1,266. But what they won’t tell you is that over the life of that loan, you’ll pay more than $206,000 in interest alone.
That’s the magic of an amortization schedule. When you hit “Calculate Amortization,” the tool generates a full table showing payment #1, #2, and all the way to #360. For each row, you see the date, the payment amount, how much went to principal, how much went to interest, your running total interest paid, and your remaining balance.
I’ll be honest—watching those early payments where 80% goes to interest can be painful. But that pain is useful. It forces you to ask better questions, like “What if I pay an extra $200 each month?”
Bi-weekly payments, extra lump sums, and the “early repayment” hack
This is where the calculator becomes genuinely fun to play with. Under “Extra Payment Options,” you can add a fixed monthly overpayment. In our example, adding just $200 per month cuts years off your loan and saves tens of thousands in interest. The results section even shows you exactly how many payments you eliminate and how much time you save.
But here’s a feature most people miss: the Early Repayment Plan. You can add specific one-time lump sums on specific dates. Let’s say you expect a $5,000 bonus next June, and another $3,000 around tax refund season. Add those dates and amounts, and the tool recalculates your entire amortization schedule around those extra payments. No other free tool I’ve found makes this so easy.
And if you’ve ever wondered whether switching to bi-weekly payments is worth it, just change the “Payment Frequency” dropdown from Monthly to Bi-Weekly. You’ll see a side-by-side comparison of how much faster you’d pay off the loan.
Loan comparison: Should you take the lower rate or shorter term?
One of the hardest decisions when borrowing is choosing between offers. A 30-year loan at 4.0% might have lower payments than a 15-year loan at 3.5%, but which one actually saves you more money over time?
That’s why the Loan Comparison tab is a lifesaver. Enter Loan 1 and Loan 2 with their respective amounts, rates, and terms. Click “Compare Loans,” and you instantly see the monthly payment difference, total interest difference, and total cost difference. A bar chart visualizes the gap, and a detailed table breaks down every number.
I used this feature last month when helping a friend decide between two auto loan offers. The lower monthly payment on the longer term looked tempting, but the comparison showed she’d pay an extra $4,200 in interest. Having that clarity before signing made the decision obvious.
Refinance analysis: Know your break-even point
Refinancing feels like a no-brainer when rates drop, but closing costs can quietly eat up your savings. The Refinance Analysis tab saves you from that trap.
You enter your current loan details (amount, rate, term, and how many years you have left) plus the new loan offer (new amount, new rate, new term, and closing costs). The tool then shows you:
- Your monthly savings (if any)
- Total interest savings over the life of the new loan
- Break-even point in months (how long until your savings exceed closing costs)
- Net savings after 5 years
If the break-even point is 36 months but you plan to sell the house in two years, refinancing might not make sense. The calculator gives you that reality check without any guesswork.
Tax savings for mortgage holders
Here’s a feature that surprised me: the Tax Information section. If you select “Mortgage (Tax Deductible)” as your loan type and enter your tax rate, the calculator estimates your total tax deduction, actual tax savings, and after-tax cost of the loan.
For a $250,000 mortgage at 4.5%, assuming a 25% tax rate, the tax savings alone could be over $50,000 over 30 years. That doesn’t change your monthly payment, but it changes how you think about the real cost of borrowing. I’ve never seen another free amortization tool include this level of detail.
Why this tool feels different (and why I keep coming back)
I’ve bookmarked a lot of calculators over the years. Most of them are either too simple to be useful or so cluttered with ads and upsells that you can’t focus. This one hits the sweet spot: it handles complex scenarios like one-time lump sums and tax deductions, yet the interface stays clean and responsive on both desktop and mobile.
And yes, the “Load Example” button is a nice touch. If you’re not sure where to start, click it once to see realistic numbers populate every field. Then tweak from there. It’s the fastest way to learn how each setting affects your loan.
Whether you’re a first-time homebuyer trying to understand amortization for the first time, a real estate investor comparing refinance offers, or just someone who wants to pay off debt faster, this tool gives you straight answers without the sales pitch. No signup, no email required, no data collection. Just a clean, local, privacy-first calculator that does one thing well: showing you exactly where your money goes, from the first payment to the last.
Give it a try with your own loan numbers. I think you’ll be surprised by what you learn about your debt in the first five minutes.
Frequently Asked Questions about Amortization Schedule Calculator
How do I sanity-check the amortization schedule result?
Rerun the calculator with a known example and compare it against the figure you expect; then swap back to your own numbers.
Which amortization schedule inputs change the outcome most?
Adjust one field at a time. The figure that shifts the result hardest is the assumption worth double-checking before you rely on it.
How much of the first mortgage payment is interest?
On a $200,000 loan at 6%, the first payment of $1,199.10 includes $1,000.00 of interest and only $199.10 of principal — about 83% goes to interest.
When does the principal portion exceed the interest portion?
On a 30-year 6% loan the split crosses 50/50 around payment 226 (year 18–19). Extra payments move that crossover earlier.
Is an online amortization schedule calculator safe to use for my real loan details?
Yes, but only if the calculator processes everything locally in your browser. The amortization calculator I use never sends your loan amount, interest rate, or any other number to a server. All calculations happen on your own device, just like running a formula in Excel. That means even if you’re entering your primary mortgage balance or a confidential business loan, no one else ever sees that data.
How do I calculate my loan amortization schedule with extra payments each month?
Enter your loan amount, interest rate, and term as usual. Then scroll down to the “Extra Payment Options” section and enter your additional monthly amount—for example, $200. Click “Calculate Amortization,” and the tool rebuilds the entire schedule around that overpayment. The results will show you how many payments you save, how much time you cut off the loan, and your total interest saved. You’ll also see the updated amortization table reflecting the faster payoff.