# US Mortgage Calculator (remote · www.usmortgagecalc.com)

US mortgage calculator and amortization API with 50-state property tax, PMI, and affordability data.

- Trust score: 88/100 (high trust)
- Change this week: 0
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-20

## Components

- remote · `www.usmortgagecalc.com`: 88/100 (this document), [markdown](https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www.md), [page](https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www)

## Channel facts

- Endpoint: `https://www.usmortgagecalc.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-09-20.

- **Endpoint Security**: 80/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 80/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 3008 tokens (~176/item across 17 items; 11 tools + 6 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 100/100
  - No destabilizing schema changes in the last 30 days.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 11 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 13 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the US Mortgage Calculator MCP server?

US Mortgage Calculator is a hosted endpoint at https://www.usmortgagecalc.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http com-usmortgagecalc-mortgage 'https://www.usmortgagecalc.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-usmortgagecalc-mortgage": {
      "url": "https://www.usmortgagecalc.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "com-usmortgagecalc-mortgage": {
      "type": "http",
      "url": "https://www.usmortgagecalc.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.com-usmortgagecalc-mortgage]
url = "https://www.usmortgagecalc.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-usmortgagecalc-mortgage": {
      "type": "remote",
      "url": "https://www.usmortgagecalc.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-usmortgagecalc-mortgage --url 'https://www.usmortgagecalc.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-usmortgagecalc-mortgage:
    url: "https://www.usmortgagecalc.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "com-usmortgagecalc-mortgage": {
      "Transport": "http",
      "Url": "https://www.usmortgagecalc.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add com-usmortgagecalc-mortgage -t streamable-http -u 'https://www.usmortgagecalc.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "com-usmortgagecalc-mortgage": {
      "type": "http",
      "url": "https://www.usmortgagecalc.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-13 (score 88, 0)

- [security] Stability: 0.97 → pass

### 2026-09-12 (score 88, +1)

No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-09 (score 87, +1)

No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-07 (score 86, +1)

No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-05 (score 85, +1)

No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-03 (score 84, +1)

No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-01 (score 83, +1)

No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-08-30 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (11)

### `calculate_mortgage` (~313 tokens)

Calculate a monthly mortgage payment

Full monthly housing cost for a US mortgage: principal and interest, property tax, homeowners insurance, mortgage insurance and HOA dues, plus lifetime totals and payoff timing. Pass a state name to use that state's average property tax rate. This is the right tool for 'what would my payment be on a $400,000 house'.

Input parameters:

- `annualInsurance` (number): Annual homeowners insurance premium in US dollars.
- `annualInterestRatePercent` (number): Annual nominal interest rate as a percentage, for example 6.5 for 6.5%.
- `downPaymentPercent` (number): Down payment as a percentage of the purchase price, 0 to 100. Not a dollar amount.
- `homePrice` (number, required): Purchase price of the home in US dollars.
- `loanTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.
- `loanType` (string): Loan programme. Affects mortgage insurance and upfront fees.
- `monthlyExtraPrincipal` (number): Additional principal paid each month. Shortens the loan rather than lowering the payment.
- `monthlyHoa` (number): Monthly homeowners association dues in US dollars.
- `propertyTaxRatePercent` (number): Annual property tax as a percentage of home value. Omit and pass `state` instead to use that state's average.
- `state` (string): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.

### `calculate_amortization` (~335 tokens)

Build an amortization schedule

Payment-by-payment breakdown of how a loan is repaid, showing the split between principal and interest and the falling balance. Use granularity 'monthly' for the first years in detail, 'yearly' for a whole-term overview. Also reports how much sooner extra principal pays the loan off.

Input parameters:

- `annualInsurance` (number): Annual homeowners insurance premium in US dollars.
- `annualInterestRatePercent` (number): Annual nominal interest rate as a percentage, for example 6.5 for 6.5%.
- `downPaymentPercent` (number): Down payment as a percentage of the purchase price, 0 to 100. Not a dollar amount.
- `granularity` (string): Yearly returns one row per year; monthly returns one row per payment, up to 600 rows.
- `homePrice` (number, required): Purchase price of the home in US dollars.
- `loanTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.
- `loanType` (string): Loan programme. Affects mortgage insurance and upfront fees.
- `monthlyExtraPrincipal` (number): Additional principal paid each month. Shortens the loan rather than lowering the payment.
- `monthlyHoa` (number): Monthly homeowners association dues in US dollars.
- `propertyTaxRatePercent` (number): Annual property tax as a percentage of home value. Omit and pass `state` instead to use that state's average.
- `state` (string): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.

### `calculate_pmi` (~294 tokens)

Calculate mortgage insurance

Mortgage insurance for any US loan programme, including the upfront charges most calculators omit. Conventional: monthly PMI and the month it cancels at 80% and 78% loan-to-value. FHA: the 1.75% upfront premium, monthly MIP, and whether it runs for the life of the loan or ends after 11 years. VA: the funding fee, tiered by down payment and prior use, and waivers. USDA: guarantee and annual fees.

Input parameters:

- `annualInterestRatePercent` (number): Annual nominal interest rate as a percentage, for example 6.5 for 6.5%.
- `creditScore` (integer): FHA only: sets the minimum down payment. 580+ qualifies for 3.5%.
- `downPaymentPercent` (number): Down payment as a percentage of the purchase price, 0 to 100. Not a dollar amount.
- `homePrice` (number, required): Purchase price of the home in US dollars.
- `loanTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.
- `loanType` (string): Loan programme. Affects mortgage insurance and upfront fees.
- `monthlyExtraPrincipal` (number): Extra principal paid monthly.
- `vaExemptFromFundingFee` (boolean): VA only: funding fee waived.
- `vaSubsequentUse` (boolean): VA only: entitlement used before.

### `calculate_property_tax` (~96 tokens)

Estimate property tax

Annual and monthly property tax for a home, using a state's average effective rate. Also returns how that state ranks nationally and how its rate compares with the national average. For the mechanics behind the number — assessment basis, caps, exemptions, appeal deadlines — use get_state_mortgage_rules.

Input parameters:

- `homePrice` (number, required): Home value in US dollars.
- `state` (string, required): Full US state name, for example "Texas".

### `calculate_affordability` (~355 tokens)

Work out how much house someone can afford

Maximum affordable home price from income, existing debt payments and available down payment, using the 28/36 qualifying ratios. Reports which of the two ratios is the binding constraint, which is the actionable part: a buyer limited by the back-end ratio can raise their budget by clearing debt, one limited by the front-end ratio cannot.

Input parameters:

- `annualGrossIncome` (number, required): Household income before tax, in US dollars per year.
- `annualInsurance` (number): Annual homeowners insurance premium.
- `annualInterestRatePercent` (number): Annual nominal interest rate as a percentage, for example 6.5 for 6.5%.
- `backEndRatioPercent` (number): Maximum total debt as a share of gross income. 36 is conservative; lenders often allow 45 and sometimes 50.
- `downPaymentAmount` (number, required): Cash available for the down payment, in US dollars. A dollar amount, not a percentage.
- `frontEndRatioPercent` (number): Maximum housing cost as a share of gross income. 28 is the conservative standard.
- `loanTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.
- `monthlyDebtPayments` (number): Existing minimum monthly debt payments: car loans, student loans, credit card minimums. Excludes housing.
- `monthlyHoa` (number): Monthly HOA dues.
- `propertyTaxRatePercent` (number): Annual property tax as a percentage of home value. Omit and pass `state` instead to use that state's average.
- `state` (string): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.

### `calculate_refinance` (~180 tokens)

Evaluate a refinance

Whether refinancing is worth it: the new payment, monthly saving, and how many months it takes to recover closing costs. Also compares lifetime interest, which catches the common trap where a lower payment costs more overall because the term was reset.

Input parameters:

- `closingCosts` (number, required): Total cost to close the refinance, in US dollars.
- `currentAnnualRatePercent` (number, required): Interest rate on the existing loan.
- `currentBalance` (number, required): Remaining principal on the existing loan.
- `currentRemainingTermMonths` (integer, required): Months still to run on the existing loan.
- `financeClosingCosts` (boolean): Roll closing costs into the new balance instead of paying cash.
- `newAnnualRatePercent` (number, required): Interest rate being offered.
- `newTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.

### `estimate_closing_costs` (~311 tokens)

Itemise closing costs

Line-by-line buyer closing costs — lender fees, title, appraisal, transfer taxes, prepaid escrow — plus total cash needed at the table including the down payment. Marks which items are worth shopping for and which are fixed by the county, and adds the FHA upfront premium, VA funding fee or USDA guarantee fee where they apply.

Input parameters:

- `annualInsurance` (number): Annual homeowners insurance premium.
- `downPaymentPercent` (number): Down payment as a percentage of the purchase price, 0 to 100. Not a dollar amount.
- `escrowMonths` (integer): Months of taxes collected up front to open the escrow account.
- `homePrice` (number, required): Purchase price of the home in US dollars.
- `loanType` (string): Loan programme. Affects mortgage insurance and upfront fees.
- `propertyTaxRatePercent` (number): Annual property tax as a percentage of home value. Omit and pass `state` instead to use that state's average.
- `state` (string): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.
- `transferTaxPercent` (number): State and local transfer tax as a percentage of price. Varies enormously by state.
- `vaExemptFromFundingFee` (boolean): VA only: exempt from the funding fee, for example a service-connected disability rating.
- `vaSubsequentUse` (boolean): VA only: entitlement has been used before.

### `calculate_rent_vs_buy` (~395 tokens)

Compare renting with buying

Compares renting and buying on net wealth rather than on monthly payment, accounting for equity, appreciation, maintenance, selling costs, and the return a renter earns on money not spent on a down payment. Returns the year buying overtakes renting. The result is highly sensitive to the appreciation and investment-return assumptions, which are returned alongside it.

Input parameters:

- `annualHomeAppreciationPercent` (number): Expected annual home price growth. The answer is highly sensitive to this.
- `annualInsurance` (number): Annual homeowners insurance premium.
- `annualInterestRatePercent` (number): Annual nominal interest rate as a percentage, for example 6.5 for 6.5%.
- `annualMaintenancePercent` (number): Annual upkeep as a percentage of home value. Typically 1 to 2.
- `annualRentIncreasePercent` (number): Expected annual rent growth.
- `downPaymentPercent` (number): Down payment as a percentage of the purchase price, 0 to 100. Not a dollar amount.
- `homePrice` (number, required): Purchase price of the home in US dollars.
- `investmentReturnPercent` (number): Return a renter earns on cash not tied up in a house.
- `loanTermYears` (integer): Loan term in years. Most US mortgages are 15 or 30.
- `monthlyHoa` (number): Monthly HOA dues.
- `monthlyRent` (number, required): Current monthly rent for a comparable home.
- `propertyTaxRatePercent` (number): Annual property tax as a percentage of home value. Omit and pass `state` instead to use that state's average.
- `sellingCostPercent` (number): Cost of selling, including agent commission.
- `state` (string): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.
- `yearsToCompare` (integer): Horizon of the comparison.

### `compare_loans` (~83 tokens)

Compare loan options side by side

Compares two to five loan scenarios and reports which is cheapest by monthly payment and which by lifetime cost, separately, because they frequently are not the same loan. Use for 15-year versus 30-year, FHA versus conventional, competing lender quotes, or with and without discount points.

Input parameters:

- `scenarios` (array, required): Two to five loan scenarios to compare side by side.

### `get_state_mortgage_rules` (~122 tokens)

Look up a state's property tax rules

How property tax actually works in one state: how assessed value is derived, any statutory growth cap, the billing cycle, named exemptions such as homestead, the filing deadline, who hears appeals and the window to file, notable county variation, and a link to the state's own tax authority. Use this when the question is about mechanics or deadlines rather than a dollar amount.

Input parameters:

- `state` (string, required): Full US state name, for example "Texas". Used to look up the average property tax rate. Either this or propertyTaxRatePercent is required.

### `list_states` (~90 tokens)

List all 50 states with property tax rates

Every US state with its average effective property tax rate, median home value and estimated annual tax. Sortable, so it answers 'which states have the highest property taxes' directly. Call this to discover valid state names for the other tools.

Input parameters:

- `limit` (integer): How many states to return.
- `order` (string): Sort direction.
- `sortBy` (string): Ordering of the returned list.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www#diagnostics

## Score history

- 2026-09-20: 88
- 2026-09-19: 88
- 2026-09-18: 88
- 2026-09-17: 88
- 2026-09-16: 88
- 2026-09-15: 88
- 2026-09-14: 88
- 2026-09-13: 88
- 2026-09-12: 88
- 2026-09-11: 87
- 2026-09-10: 87
- 2026-09-09: 87
- 2026-09-08: 86
- 2026-09-07: 86
- 2026-09-06: 85
- 2026-09-05: 85
- 2026-09-04: 84
- 2026-09-03: 84
- 2026-09-02: 83
- 2026-09-01: 83
- 2026-08-31: 82
- 2026-08-30: 82
- 2026-08-29: 81
- 2026-08-28: 81
- 2026-08-27: 80
- 2026-08-26: 80
- 2026-08-25: 79
- 2026-08-24: 78
- 2026-08-23: 78
- 2026-08-22: 77

## Common questions

### What is the US Mortgage Calculator MCP server?

US Mortgage Calculator is an MCP server listed in the public MCP registry as com.usmortgagecalc/mortgage. US mortgage calculator and amortization API with 50-state property tax, PMI, and affordability data. This page covers its hosted endpoint (https://www.usmortgagecalc.com/mcp).

### Is the US Mortgage Calculator MCP server safe to use?

US Mortgage Calculator scores 88 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the US Mortgage Calculator MCP server expose?

US Mortgage Calculator exposes 11 tools: calculate_mortgage, calculate_amortization, calculate_pmi, calculate_property_tax, calculate_affordability, and 6 more. Their descriptions and schemas cost roughly 2,574 tokens of context every time the server is loaded.

### Does the US Mortgage Calculator MCP server require authentication?

No. We connected to US Mortgage Calculator without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the US Mortgage Calculator MCP server still maintained?

US Mortgage Calculator is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://www.usmortgagecalc.com/mcp
- Website: https://www.usmortgagecalc.com/
- Changelog RSS feed: https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www.json
- HTML version of this page: https://verifymcp.io/servers/com-usmortgagecalc-mortgage/www