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
When should I use "How much will my payment be?" vs "How much can I borrow?"
Use Mode A when you already know the loan amount and want to confirm the payment fits your budget — for example, after a lender quotes you a loan. Use Mode B when you're shopping and know your ceiling: "I can afford $400/month — how much can I borrow?" Mode B is especially useful for car and personal loan shopping, letting you set a budget before you find the product.
What debt-to-income ratio do lenders use for loan approval?
Most lenders look at your back-end DTI: total monthly debt payments divided by gross monthly income. The threshold varies by loan type: conventional mortgages allow up to 43–45%, FHA mortgages up to 50% with compensating factors, personal and auto loans typically 36–43%. A DTI above 43% signals to most lenders that you're overleveraged. If your DTI is high, Mode B can help you find a loan amount that keeps you within the threshold.
What is the difference between APR and interest rate?
The interest rate is the base cost of borrowing — what this calculator uses to determine your payment. APR (Annual Percentage Rate) includes the interest rate plus fees (origination, closing costs, etc.) amortized over the loan. APR is always higher than or equal to the interest rate, and it's the number to compare across lenders. When entering a rate here, use the APR if you want to see the true effective cost including fees.
Does getting pre-qualified or pre-approved affect my credit score?
Pre-qualification uses a soft inquiry — no credit score impact. Pre-approval uses a hard inquiry, which typically drops your score 2–5 points temporarily. For shopping purposes, FICO treats multiple hard inquiries for the same loan type within 14–45 days as a single inquiry. So rate-shopping with 3–4 lenders in a two-week window causes no more score damage than applying once. Use this calculator to filter to realistic offers before any hard inquiries.
How do I compare loan offers from different lenders?
Compare three numbers: APR (total cost including fees), monthly payment, and total of payments. A lower monthly payment often means a longer term — which can cost more total. A slightly higher rate with no origination fee can be cheaper overall than a lower rate with a 2–3% origination fee. Use Mode A to calculate the payment for each lender's quoted rate and term, then compare total payments side by side.
What happens if I can only make minimum payments on a loan?
With installment loans (personal, auto, mortgage), your minimum payment IS the calculated payment — there's no "minimum payment trap" like with credit cards. You must pay the full amount each period. Missing payments triggers late fees and credit score damage. If you're concerned about affordability, use Mode B to back-calculate a loan amount that produces a payment you're certain you can make even in a lean month.
Can I use this calculator for any type of fixed-rate loan?
Yes — mortgages, personal loans, auto loans, student loans, home equity loans, and any other fixed-rate installment debt. The underlying formula is identical across all fixed-rate loan types. Variable-rate loans are different: the payment adjusts when the rate changes, so this calculator only shows the payment at the initial rate. For variable loans, use the initial rate to estimate your starting payment.