Press kit
Everything needed to write about, cite or reproduce this site. All data is free to use under CC-BY-4.0 — no permission required, credit appreciated.
Fact sheet
- Calculators
- 15
- States covered
- 50
- API operations
- 11
- Glossary terms
- 45
- Open datasets
- 5
- Data licence
- CC-BY-4.0
What it is
A free mortgage calculator for all 50 US states. Three things make it different from the rest of the category.
- Property tax is modelled per state. Effective rates run from 0.28% in Hawaii to 2.49% in New Jersey. A calculator applying a national average is wrong by hundreds of dollars a month at either end.
- Every assumption is published. Each rate, fee and threshold carries a source, a source URL and the year it takes effect. Almost no calculator in this category can produce that on request.
- The engine is open to machines as well as people. A REST API and an MCP server expose the same 11 operations the website uses, with no key and no rate limit.
A statistic you can use
The same $400,000 home costs $737 more a month in property tax in New Jersey than in Hawaii — $8,840 a year.
That gap is larger than the payment difference between a 6.5% and a 7.5% mortgage rate on the same house. Derived from our state property tax dataset; the full method is on the methodology page. Free to reproduce with attribution.
Boilerplate
US Mortgage Calculator is a free mortgage calculator covering all 50 US states, with property tax, insurance and mortgage insurance modelled per state. Its calculation engine, reference data and formulas are published openly and available as a REST API and an MCP server for AI assistants.
US Mortgage Calculator (usmortgagecalc.com) is a free mortgage calculation tool covering all 50 US states. Unlike most calculators, it models property tax from state-level effective rates rather than a national average, includes mortgage insurance for conventional, FHA, VA and USDA loans, and publishes every formula and assumption it applies with an attributed source and effective year.
The same calculation engine powers the website, a public REST API and a Model Context Protocol server, so figures from any surface agree by construction rather than by convention. The reference data is downloadable as CSV and JSON under a CC BY 4.0 licence.
The site is published by DevScriptify. It is not a lender or a mortgage broker, sells no leads, and has no affiliate relationship with any lender.
Publisher and contact
Publisher
DevScriptify. Independent, not a lender or mortgage broker, sells no leads, and has no affiliate relationship with any lender. The site is funded by display advertising.
Media contact
For interviews, custom data cuts, or fact-checking a figure before publication.
Happy to pull a specific slice of the dataset — by state, by price band, by loan programme — and send it as a spreadsheet.
Brand assets
The wordmark is set in Inter: US Mortgage in the foreground colour and Calculator in the brand navy, #103159.
Files
- Mark, SVG — scales to any size
- Social card, PNG — 1800 × 945
- App icon, PNG — 180 × 180
Screenshots
Rather than ship stills that age, take your own from the live pages — the calculator, the datasets or the API explorer. No permission needed. Ask if you want a specific view captured at a particular size.
Using our data
All five datasets are published under Creative Commons Attribution 4.0 International: free to reproduce, adapt and use commercially, with credit. Ready-made citations in APA, MLA, Chicago, BibTeX and RIS are on the datasets page.
If a figure looks wrong, please tell us before publishing — every source is published so it can be checked, and a correction is faster than a retraction.