Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Monthly payment
$635.99
Total interest
$2,896
Total paid
$22,896
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter loan amount ($).
- 2Enter interest rate (%).
- 3Enter loan term (months).
- 4Read your monthly payment on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
A generic amortizing loan calculator — works for personal loans, student loans, or any fixed-rate borrowing.
Worked example
Using the values the calculator loads with:
Inputs
- Loan amount: 20000 $
- Interest rate: 9 %
- Loan term: 36 months
Results
- Monthly payment: $635.99
- Total interest: $2,895.81
- Total paid: $22,895.81
What each field means
Inputs
- Loan amount ($)
- The loan amount used in the calculation, measured in $. Starts at 20000 $ so you have a working example on load.
- Interest rate (%)
- The interest rate used in the calculation, measured in %. Starts at 9 % so you have a working example on load.
- Loan term (months)
- The loan term used in the calculation, measured in months. Starts at 36 months so you have a working example on load. Accepted range: 1–360 months.
Results
- Monthly payment
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total interest
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total paid
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the loan calculator work?
A generic amortizing loan calculator — works for personal loans, student loans, or any fixed-rate borrowing.
What do I need to enter?
3 values: loan amount, interest rate, and loan term. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the monthly payment result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Loan Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/loan
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/loan" target="_blank" rel="noopener">Loan Calculator — RevenueLab</a> (2026).</p>
Source: [Loan Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/loan) (2026).