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
Affordable home price
$377,069
Supported loan amount
$339,362
Down payment needed
$37,707
Max total housing payment
$2,750.00
Of that, principal + interest
$2,145.00
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter gross annual income ($).
- 2Enter other monthly debt ($).
- 3Enter max dti (%).
- 4Enter interest rate (%).
- 5Enter term (years).
- 6Enter down payment (%).
- 7Read your affordable home price on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Lenders size a mortgage against your gross income and existing debt. The common guardrail is a 36% back-end debt-to-income ratio, meaning all monthly debt including the new mortgage stays under 36% of gross monthly income.
Worked example
Using the values the calculator loads with:
Inputs
- Gross annual income: 110000 $
- Other monthly debt: 550 $
- Max DTI: 36 %
- Interest rate: 6.5 %
- Term: 30 years
- Down payment: 10 %
Results
- Affordable home price: $377,069.12
- Supported loan amount: $339,362.21
- Down payment needed: $37,706.91
- Max total housing payment: $2,750.00
- Of that, principal + interest: $2,145.00
What each field means
Inputs
- Gross annual income ($)
- The gross annual income used in the calculation, measured in $. Starts at 110000 $ so you have a working example on load.
- Other monthly debt ($)
- The other monthly debt used in the calculation, measured in $. Starts at 550 $ so you have a working example on load.
- Max DTI (%)
- The max dti used in the calculation, measured in %. Starts at 36 % so you have a working example on load. Accepted range: 10–55 %.
- Interest rate (%)
- The interest rate used in the calculation, measured in %. Starts at 6.5 % so you have a working example on load.
- Term (years)
- The term used in the calculation, measured in years. Starts at 30 years so you have a working example on load.
- Down payment (%)
- The down payment used in the calculation, measured in %. Starts at 10 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Affordable home price
- 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.
- Supported loan amount
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Down payment needed
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Max total housing payment
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Of that, principal + interest
- 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 house affordability calculator work?
Lenders size a mortgage against your gross income and existing debt. The common guardrail is a 36% back-end debt-to-income ratio, meaning all monthly debt including the new mortgage stays under 36% of gross monthly income. The underlying maths is: Max payment = (Gross monthly income × DTI%) − existing debt. Loan is back-solved from that payment.
What do I need to enter?
6 values: gross annual income, other monthly debt, max dti, interest rate, term, and down payment. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the affordable home price 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). House Affordability Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/house-affordability
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/house-affordability" target="_blank" rel="noopener">House Affordability Calculator — RevenueLab</a> (2026).</p>
Source: [House Affordability Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/house-affordability) (2026).