How the figures are built

Every figure on this site starts from a federal file or from a state agency's own page. Nothing is copied from a lender, a lead site or another calculator, and nothing you type leaves your browser. This page sets out the data, the rules the calculator applies, how amounts and payments are computed, and what is left out. Edition of October 21, 2026; mortgage rate of October 15, 2026.

The federal files

• HUD fiscal year 2026 income limits (county file), effective May 1, 2026: median family income for four people and the 80% low-income limit for one to eight people, for 4,680 counties, county parts and New England towns. US government work, public domain.
• FHFA 2026 conforming loan limits: $832,750 in most counties, up to $1,249,125 in high-cost areas, one unit.
• HUD FHA forward mortgage limits for 2026, with Mortgagee Letter 2025-23: floor $541,287, ceiling $1,249,125, $1,873,625 in Alaska and Hawaii.
• Freddie Mac Primary Mortgage Market Survey: the 30-year fixed average, 7.4% in the week of October 15, 2026, used as the default rate. Read again every Thursday by a script.

One HUD area has no conforming limit of its own in the FHFA file: Sullivan part (MO), a part of a county that HUD lists separately; the calculator shows "…" there.

Income against the area median

HUD publishes the median for a family of four. For other sizes the calculator applies HUD's own adjustment: 1 person 70%, 2 people 80%, 3 people 90%, 4 people 100%, 5 people 108%, 6 people 116%, 7 people 124%, 8 people 132%. Your share of area median income is your gross household income divided by that adjusted median. HUD's published 80% limit is shown as HUD prints it: it can differ from 80% of the median where HUD caps it at the national median or raises it in high-cost areas.

The state programs

For each state, we read the agency's program pages and lender guides and wrote down, for every program: the amount and how it is computed, the form (grant, forgivable, deferred, repayable), the forgiveness period, the first-time buyer rule, the minimum credit score, the income and price limits, the first mortgages it pairs with, its status, and the exact sentence of the agency that supports the amount. When an agency's site refused automated reading, the terms were taken from the text of its official pages as indexed by a search engine, and the program carries that note. Texas, Ohio and New Jersey publish county tables of income and price limits that we transcribed in full, with checks against rows read by eye.

How the calculator decides

A program is marked "does not fit" when your figures break a rule we hold: income above the agency's limit for your county and household size, price above its limit, a credit score below its floor, a first mortgage type it does not use, or a first-time requirement you do not meet (veterans and targeted areas are exempt in most programs, which the reason says). It is marked "check with the agency" when a limit is set county by county in a table we have not transcribed, when its first-time rule depends on the first mortgage, or when it has a condition we cannot test. It is marked "not taking applications" when the agency says its funds are reserved or its portal closed.

The amount is computed as the agency writes it: a percentage of the price or of the first mortgage, with its floor and cap, a fixed sum, the county amount in New Jersey. The first mortgage is the price minus the minimum down payment of the loan type: 3.5% for FHA with a score of 580 or more and 10% below (HUD Handbook 4000.1), 3% conventional (Freddie Mac), nothing for VA and USDA. The FHA upfront premium, often financed, is left out, which understates a 5%-of-loan amount by under 2%. When a program offers 3%, 4% or 5%, the calculator shows the highest; the lender sets which applies.

Payments

Monthly payment = principal and interest on the first mortgage over 30 years at the rate you enter, the standard annuity formula. With help: the same first mortgage, plus the agency's rate add-on when it publishes one (0.40 point for SONYMA), plus the monthly payment of a repayable second loan at its published rate and term. Taxes, insurance and mortgage insurance are not included, because they depend on the home and the insurer.

What is left out

City, county and nonprofit programs, except those a state agency's guide names, which appear on the state page without an amount in the calculator. Assets limits and debt-to-income ratios, which the lender checks. Targeted-area limits, higher than the ones used here. States whose agency pages we have not read yet: they get every federal figure and no program.

Checks and updates

Automated tests rebuild known figures before each release: HUD values for named counties, the Texas, Ohio and New Jersey table rows read by eye, MassHousing's own payment example ($161 a month for $25,000 over 15 years at 2%), the forgiveness schedules and the IRS cap on mortgage credit certificates. A script reads the Freddie Mac rate every week and looks for next year's federal files; program terms are read again by hand when an agency announces a change.