Payment Calculator
Calculate a monthly payment or find the maximum loan amount you can afford — two tools in one.
Tip: Use this when shopping for a loan — confirm a payment fits your budget, or find what you qualify for based on a target monthly amount.
Monthly Payment
$373.28
Fixed for the life of the loan
Total Periods
48
Payoff Date
—
Results are estimates for educational purposes. Not financial advice. See disclaimer.
Amortization Schedule
| Year | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $4,479.31 | $3,261.67 | $1,217.63 | $11,738.33 |
| 2 | $4,479.31 | $3,567.64 | $911.67 | $8,170.68 |
| 3 | $4,479.31 | $3,902.31 | $577.00 | $4,268.37 |
| 4 | $4,479.31 | $4,268.37 | $210.93 | $0.00 |
How to Use This Payment Calculator
This calculator has two modes, and switching between them takes one click. Use whichever fits your situation — both use the same underlying loan math and give you a full amortization schedule.
Mode A: "How much will my payment be?"
You know the loan amount. Enter the principal, term, and rate — and you'll see the exact monthly payment, total interest, and full amortization schedule. This is the mode to use when you've received a loan offer or are modeling a specific amount. Example: a $15,000 personal loan at 9% for 4 years comes out to $373/month, with $2,904 in total interest.
Mode B: "How much can I borrow?"
You know your budget. Enter the monthly payment you can afford, your expected rate, and the term — and the calculator tells you the maximum loan amount that fits. Example: if you can handle $400/month at 9% for 4 years, you can borrow up to ~$16,073. This is the mode to use before shopping — it anchors your search to what you can realistically afford rather than stretching toward what's available.
Practical tips for both modes
The interest rate matters more than most people expect. On a $15,000 loan for 4 years, the difference between 7% and 13% is $44/month — and nearly $2,100 in total interest. Before committing, try the rate your bank quotes, then check rates at a credit union (typically 1–2% lower) and an online lender. Enter all three into Mode A to see exactly how much each option costs.
How the Inverse Formula Works (Mode B)
Mode B uses the mathematical inverse of the standard amortization formula. Where Mode A solves for M (monthly payment) given P (principal), Mode B solves for P given M:
Both formulas use the same variables: P = principal, M = monthly payment, r = monthly interest rate (annual ÷ 12 ÷ 100), n = total months. The results are mathematically exact — if you take the Mode B max loan amount and run it through Mode A with the same rate and term, you'll get back the exact payment you entered.
Why the term dramatically changes the max loan
At $400/month and 9% interest, the max loan amount changes dramatically with term length:
- 24 months: ~$8,700 max
- 36 months: ~$12,600 max
- 48 months: ~$16,073 max
- 60 months: ~$19,200 max
The longer term lets you borrow more for the same payment — but increases total interest paid. The sweet spot is generally the shortest term you can afford, because borrowing power and interest savings both favor it.
Debt-to-Income and Affordability
Lenders evaluate loan applications using your debt-to-income ratio (DTI): total monthly debt payments divided by gross monthly income. To calculate yours: add up all monthly debt obligations (rent/mortgage, car payments, student loans, credit card minimums) and divide by your pre-tax monthly income.
Most personal and auto lenders want your total DTI below 36–43%. If you earn $5,000/month (gross) and already have $1,200 in monthly debt payments, your current DTI is 24%. Adding a $400/month loan brings it to 32% — still within most lenders' comfort zone. Exceeding 43% makes approval harder and rates higher. Mode B is a practical tool for finding the loan amount that keeps your DTI in a healthy range.
Frequently Asked Questions
Sometimes you don't know your payment amount — sometimes you don't know how much you can borrow, or what interest rate fits your budget. A payment calculator solves for any unknown variable in the loan equation.
What can a payment calculator solve for?
Our payment calculator works in any direction: enter loan amount, rate, and term to find the monthly payment. Or enter what payment you can afford to find the maximum loan amount. Or enter loan amount and target payment to find the rate you need.
How do I figure out how much loan I can afford with my monthly budget?
Decide what monthly payment fits your budget, then enter it along with the current interest rate and your desired loan term. The calculator shows the maximum loan amount that produces that payment. Most lenders also recommend total debt payments stay below 36% of gross monthly income.
What interest rate would make a loan fit my budget?
Enter the loan amount, your target monthly payment, and the loan term. The calculator solves for the interest rate that makes those numbers work. This is useful for evaluating refinancing options — if rates drop below this number, refinancing might save you money.
Should I focus on lowering my payment or paying off debt faster?
Depends on your priority. Lower payments improve cash flow but increase total cost. Faster payoff saves on interest but stresses monthly budget. Most experts suggest paying just enough extra to be comfortable while building emergency savings — typically $100–300 above minimum.
How accurate is this payment calculation compared to what a lender will offer?
The math is identical to what lenders use. However, lender quotes may include PMI, taxes, insurance, and fees that aren't part of the basic loan payment. The pure principal-and-interest calculation here matches what's quoted as your "P&I" by lenders.