Editorial Guidelines

Our Commitment to Accuracy

Amortio exists to help people make informed financial decisions through precise, transparent, and reliable loan calculation tools. Accuracy is not just a goal for us; it is the foundation of everything we build and publish. Every number our calculators produce, every statistic in our blog articles, and every data point on our mortgage rate pages is held to the highest standard of accuracy we can achieve.

We recognize that financial calculations carry real consequences. An incorrect amortization schedule could lead someone to underestimate their total interest payments by thousands of dollars. An inaccurate affordability estimate could set unrealistic expectations during the home-buying process. Because of these stakes, we treat every calculation as if our users will base actual financial decisions on it, because many of them do.

Our commitment to accuracy means we would rather display a transparent limitation notice than present a number we cannot fully verify. When our calculators cannot account for certain variables, such as lender-specific fees, property taxes in specific jurisdictions, or adjustable-rate mortgage resets beyond initial periods, we clearly state those limitations alongside the results.

How We Source Our Formulas

The mathematical formulas used in all Amortio calculators are derived from established actuarial and financial mathematics standards. We do not invent proprietary formulas or use approximations where exact solutions exist. Our primary calculation methods include:

Standard Amortization Formula

Our core loan amortization calculator uses the standard fixed-rate mortgage payment formula, which calculates the periodic payment amount for a fully amortizing loan. This formula has been used by financial institutions, actuaries, and regulatory bodies for decades and is mathematically proven to produce exact results for fixed-rate loans with constant payment amounts. It accounts for the time value of money and the compounding effect of interest over the loan term.

Actuarial Methods

For calculations involving variable payment schedules, extra payments, and early payoff scenarios, we employ standard actuarial methods recognized by the American Academy of Actuaries and consistent with practices described in financial mathematics textbooks such as Kellison's The Theory of Interest and Broverman's Mathematics of Investment and Credit. These methods ensure that interest accrual and principal reduction are computed correctly for each payment period, even when payment amounts change.

Debt-to-Income and Affordability Calculations

Our DTI calculator and affordability calculator follow the conventional and FHA lending guidelines established by Fannie Mae (Selling Guide B3-6), Freddie Mac, and the Federal Housing Administration. The front-end ratio threshold of 28% and back-end ratio threshold of 36% used in our affordability calculations reflect widely accepted industry standards, though we note that individual lenders may apply different criteria.

PMI Estimation

Private Mortgage Insurance estimates in our PMI calculator are based on published rate tables from major PMI providers and industry averages reported by the Urban Institute and the Mortgage Bankers Association. Since actual PMI rates vary by credit score, loan-to-value ratio, and insurer, we present ranges and clearly label results as estimates.

Refinance Break-Even Analysis

Our refinance calculator uses net present value analysis to determine the break-even period, accounting for closing costs, rate differentials, remaining loan balance, and the opportunity cost of the closing cost outlay. This approach is consistent with the methodology recommended by the Consumer Financial Protection Bureau (CFPB) in their mortgage refinancing guidance.

Fact-Checking Process

Every piece of content published on Amortio, whether it is a blog article, a data-driven page, or an update to our calculator logic, goes through a structured fact-checking process before publication:

Step 1: Source Verification

All factual claims must be traceable to a primary source. We prioritize government data sources (Federal Reserve, Bureau of Labor Statistics, Census Bureau, CFPB), peer-reviewed research, and official publications from recognized financial institutions and industry organizations. Secondary sources such as news outlets are used only for context and are cross-referenced against primary data.

Step 2: Numerical Validation

Any numerical data presented in our content, including statistics, percentages, rates, and calculated figures, is independently verified against the cited source. When data is derived from calculations rather than direct citation, the calculation methodology is documented and reviewed.

Step 3: Formula Verification

Before any calculator formula is deployed, it is tested against known correct results from multiple independent sources. We compare our outputs against published amortization tables from the Federal Reserve, example calculations from the CFPB, and results from established financial calculators to ensure consistency. Any discrepancy triggers a detailed investigation before the code is released.

Step 4: Content Review

Blog articles and educational content are reviewed for accuracy of financial terminology, correctness of described processes, and alignment with current regulations and market practices. Claims about lending practices, rates, or regulations are verified against current guidelines from relevant regulatory bodies.

Step 5: Final Accuracy Check

Before publication, a final review confirms that all links to sources are functional, all cited data matches the source, and all calculator results align with expected outputs across a range of input scenarios including edge cases (very large loans, very short terms, very high or low interest rates, zero down payment scenarios).

How We Handle Rate Data

Mortgage rate data presented on our city, state, and zip code pages comes from authoritative, publicly available data sources. We do not fabricate rate figures or use unverifiable proprietary data. Our primary sources include:

Federal Reserve Economic Data (FRED)

The Federal Reserve Bank of St. Louis maintains the FRED database, which provides historical and current data on mortgage rates, Treasury yields, and other economic indicators. We use FRED data series including the 30-year fixed-rate mortgage average (MORTGAGE30US) as baseline rate references. This data is sourced directly from the Federal Reserve's primary statistical releases.

Freddie Mac Primary Mortgage Market Survey (PMMS)

The PMMS has been the benchmark mortgage rate survey since 1971. Freddie Mac surveys lenders nationwide each week to produce average rates for 30-year fixed, 15-year fixed, and 5/1 adjustable-rate mortgages. We reference PMMS data as the gold standard for current national average mortgage rates and clearly note the survey date when presenting this data.

Bureau of Labor Statistics (BLS)

For content involving housing affordability, wage-to-mortgage ratios, and cost-of-living comparisons across metropolitan areas, we reference BLS data including the Consumer Price Index (CPI), median wage data from the Occupational Employment and Wage Statistics (OEWS) survey, and metropolitan area employment statistics.

U.S. Census Bureau

Housing data including median home values by city and state, homeownership rates, and housing stock characteristics come from Census Bureau sources including the American Community Survey (ACS), the Current Population Survey/Housing Vacancy Survey, and decennial census data. We specify the survey year when citing Census data to avoid presenting outdated figures as current.

How City and State Pages Work

Our programmatic city and state mortgage rate pages combine national average rate data with localized housing market data from the Census Bureau and BLS. The rates shown on city pages represent nationally available mortgage rates contextualized with local median home values, median household incomes, and cost-of-living indices. We clearly state on each page that the rates shown are national averages and that actual rates offered to borrowers will vary based on their credit profile, down payment, and specific lender.

Transparency and Disclosure Policy

Transparency is a core value at Amortio. We believe our users deserve to know exactly how our tools work, where our data comes from, and what limitations exist. Our transparency commitments include:

• Open Methodology: Our Methodology page explains every formula and calculation method we use in plain language and mathematical notation. Users can verify our calculations independently.
• Source Attribution: When we cite statistics, rates, or data, we identify the source and, where possible, provide a link to the original data. We do not use anonymous or unverifiable data sources for factual claims.
• Limitation Notices: Each calculator includes clear documentation of what it does and does not account for. We would rather under-promise and provide accurate results than over-promise with unreliable estimates.
• No Hidden Agendas: Amortio does not receive compensation from lenders, banks, or financial institutions for directing users to specific products or services. Our calculators and content are designed to educate, not to sell.
• Advertising Disclosure: Amortio is supported by advertising revenue. Display advertisements on our site are served by third-party ad networks and are clearly distinguishable from our editorial content. Advertisers have zero influence over our calculator logic, data sources, or editorial content.
• Data Freshness: When we present data that may become outdated, such as current mortgage rates, we include the date of the data alongside the figures. We do not present stale data as current information.

Correction Policy

Despite our rigorous fact-checking process, errors may occasionally occur. When they do, we are committed to correcting them promptly, transparently, and completely. Our correction policy operates on these principles:

Reporting Errors

Users who identify potential errors in our calculators, data, or content are encouraged to report them via our Contact page or by emailing [email protected]. We review every error report and respond with our findings.

Calculator Errors

If a calculation error is confirmed, we treat it as a critical issue. The fix is prioritized, tested against known correct results, and deployed as quickly as possible. If the error could have led users to materially incorrect financial conclusions, we note the correction on the affected page with the date the fix was applied.

Content Errors

Factual errors in blog articles and educational content are corrected in-place. Significant corrections are noted at the top of the article with the date and nature of the correction. Minor corrections (typos, formatting issues, broken links) are made without formal notation.

Data Errors

If data on our city, state, or zip code pages is found to be incorrect, we update it and regenerate the affected pages. If the error originates from an upstream data source, we note the discrepancy and, if necessary, temporarily remove the incorrect data until a verified replacement is available.

Independence from Financial Institutions

Amortio operates with complete editorial and operational independence from banks, lenders, mortgage brokers, and other financial institutions. This independence is fundamental to our ability to provide unbiased tools and information. Specifically:

• No Affiliate Links: Amortio does not use affiliate links to lenders or financial products. We do not earn commissions by directing users to specific banks, mortgage companies, or loan products. This distinguishes us from many competing calculator sites that monetize through lead generation.
• No Lead Generation: We do not collect user information for the purpose of selling leads to lenders. Your financial data stays in your browser, and your contact information is never shared with third parties for marketing purposes.
• No Sponsored Content: We do not accept paid placements, sponsored articles, or "brought to you by" content from financial institutions. All editorial content reflects our independent analysis and research.
• No Lender Partnerships: Our calculator results are not influenced by partnerships with specific lenders. We do not adjust default rates, fees, or terms to favor any particular institution.
• Revenue Model: Amortio is funded through contextual display advertising, not through financial product referrals. This business model ensures that our incentives are aligned with providing accurate, helpful tools that attract and retain users, rather than steering users toward specific financial products.

Author and Contributor Standards

Contributors to Amortio's content are expected to meet the following standards:

Domain Knowledge

Contributors writing about financial topics must demonstrate working knowledge of the subject matter. This includes understanding of loan amortization mechanics, mortgage industry practices, relevant federal and state regulations, and the mathematical foundations of financial calculations.

Research Standards

All contributors are required to base their content on verifiable primary sources. Personal opinions must be clearly identified as such and separated from factual statements. Contributors must cite their sources and provide sufficient information for readers and editors to verify claims independently.

Objectivity

Content must be written with objectivity and balance. Contributors may not have financial conflicts of interest related to the topics they cover. If a potential conflict exists, it must be disclosed and the content will be assigned to an alternative contributor or subjected to additional editorial review.

Compliance with Guidelines

All contributors agree to follow these editorial guidelines, including the fact-checking process, source attribution requirements, and correction procedures. Submissions that do not meet these standards will be returned for revision.

Data Quality and Integrity

Financial data accuracy is the backbone of every tool and page on Amortio. We maintain strict data quality standards throughout our content pipeline:

Data Provenance

Every data point displayed on Amortio must have a documented provenance chain: the original source, the date of publication, the method of collection, and any transformations applied before display. We do not use data from anonymous sources, social media, or unverifiable origins for factual claims. When multiple sources report different figures for the same metric, we use the most authoritative source (government agency over industry report, primary survey over secondary analysis) and note the discrepancy when material.

Statistical Methodology

When our content references statistical measures such as averages, medians, percentiles, or growth rates, we ensure the underlying methodology is appropriate for the claim being made. For example, we use median rather than mean when discussing home prices, because median is more representative of typical home values and less distorted by extreme outliers. When we present year-over-year changes, we specify whether the comparison is nominal or inflation-adjusted.

Data Freshness Standards

Different types of data have different freshness requirements. Current mortgage rates are updated weekly from the Freddie Mac PMMS release. Median home values and income data from the Census Bureau are updated annually when new American Community Survey estimates become available. Regulatory information is updated within 30 days of any change. We include publication dates alongside all data and never present stale data without noting its vintage.

Handling Conflicting Data

In cases where reputable sources publish conflicting figures (for example, different homeownership rate estimates from the Census Bureau and the Federal Reserve), we prefer the source with the larger sample size and more rigorous methodology. When the conflict is significant enough to affect user understanding, we present both figures with their respective sources rather than choosing one and ignoring the other.

User Privacy in Content Production

Our editorial process respects user privacy at every stage:

• No User Data in Content: We never incorporate individual user data, calculations, or interactions into our published content. Case studies and examples use hypothetical scenarios with clearly fictional figures.
• No Tracking-Based Content: We do not use analytics data about user behavior to personalize or alter the financial content, calculations, or data presented to individual users. Every user sees the same information for the same inputs.
• Contact Privacy: When users contact us with corrections, questions, or feedback, their personal information is never published or shared. Error reports that lead to corrections credit the nature of the correction without identifying the reporter unless they request attribution.
• No User Testimonials: We do not solicit or publish user testimonials about financial outcomes. Financial results are highly individual, and presenting specific outcomes could be misleading to other users with different circumstances.

For complete details on how we handle user data, see our Privacy Policy. For information about how our calculators process data entirely client-side, see our Methodology page.

Review Cadence

Ensuring content accuracy is an ongoing process, not a one-time task. Our review schedule is designed to keep all content current and reliable:

• Calculator Logic: Reviewed and tested after every code update. Full regression testing is performed quarterly to verify continued accuracy across all input ranges.
• Mortgage Rate Data: National average rates are updated weekly based on the latest Freddie Mac PMMS release. City and state pages are regenerated with updated data on a regular schedule.
• Blog Articles: Reviewed at least once every six months to ensure that cited statistics remain current, regulatory references are still accurate, and linked resources are functional.
• Mortgage Statistics Page: Comprehensive review of all statistics, sources, and data points is conducted quarterly. Individual data points are updated as new reports from primary sources become available.
• Legal and Regulatory Content: Reviewed within 30 days of any significant regulatory changes from the CFPB, Federal Reserve, or other relevant regulatory bodies.
• Full Site Audit: A comprehensive review of all pages, calculators, and content is conducted every six months. This audit checks for broken links, outdated information, calculator accuracy, and alignment with current editorial guidelines.

Regulatory Awareness

Financial content operates in a heavily regulated environment. While Amortio does not provide financial advice, our educational content must accurately reflect the regulatory landscape:

• CFPB Guidance: We monitor Consumer Financial Protection Bureau publications, enforcement actions, and updated guidance to ensure our content reflects current regulatory expectations for mortgage lending, disclosure requirements, and consumer protections.
• TILA and RESPA: Content referencing loan disclosures, closing costs, or lender requirements is reviewed against the Truth in Lending Act (TILA) and Real Estate Settlement Procedures Act (RESPA) requirements to ensure accuracy.
• State-Level Variations: When our content discusses regulations that vary by state (such as mortgage recording taxes, prepayment penalties, or foreclosure procedures), we note the state-specific nature of the information and recommend consulting local professionals.
• Regulatory Updates: When significant regulatory changes occur (such as changes to conforming loan limits, FHA insurance premiums, or QM standards), we update affected content within 30 days and note the regulatory change that prompted the update.

We explicitly state on all relevant pages that Amortio provides educational information, not legal or financial advice, and that users should consult qualified professionals for decisions about their specific circumstances.