Square Footage Guides

Who Writes These, and What "Checked" Means Here

FootyCalc is an independent publication owned and operated by Richard Taylor in Juneau, Alaska. There is no editorial board behind these pages, and we are not going to describe one. What exists instead is a procedure you can audit from the outside:

• Every guide ends with a list of the pages and documents its claims were read from, with the wording it quotes.
• Arithmetic on every guide is re-derivable with the numbers printed on the page — no figure is asserted that the reader cannot reproduce.
• Claims that could not be traced to a fetched source were deleted rather than softened. Four guides keep a section headed "What We Could Not Verify" that names what was removed.
• Every link that leaves this site carries rel="nofollow", including the sources. Outbound links lend no authority, and a citation you can click is still a citation.

A common version of this paragraph reads "every guide is reviewed against publicly available US standards." That would overstate it. Measured against the eleven published pages today: six mention ANSI Z765, eight cite NIST Special Publication 811, three use Census Bureau housing data, and 11 of 11 cite at least one .gov domain. That last number was 10 of 11 until October 13, 2026, when the page with no federal source — this hub's own first row — went through the re-check.

The Guides, With the Numbers That Describe Them

Competitor hubs list guide titles. This index also publishes how much evidence sits behind each one. The columns below were measured from the published pages on October 13, 2026, not typed from memory; the method and the exact commands are in the sources list at the bottom. Three rows have moved since this table was first published, and every move changed the summary cells under it. On October 7 the printable cheat sheet's re-check flipped the federal-source tally from 9 of 11 to 10 of 11. On October 11 the cubic-feet guide went from 2,919 words and four links across three domains to 4,776 words and seven links across five. On October 13 the top-level square footage article went from 2,849 words and two links across one domain to 4,506 words and six links across four, and that single row took the federal-source tally from 10 of 11 to 11 of 11 — the page that cited no .gov source was the thinnest row in the table, which is exactly the kind of thing an index should not get to hide. A stale row is a page making numbers up.

Reading the columns honestly: "page words" counts everything a crawler receives after scripts, styles and icons are stripped — including the shared navigation and footer, which measure 485 words on our empty 404 page. Subtract roughly 485 from each row for the article itself; the eleven pages total about 41,900 article words. "Domains cited" is distinct external hosts linked by that page, and "source links" is the links themselves — the linear-feet guide links ten times across nine hosts and names errors it found on three of them. All 69 links off this site are nofollow. "FAQs" counts the questions visible on the page, which are mirrored one-to-one in its FAQPage structured data. Two pages carry no calculator: the printable sheet, and the room-size data report, which is a reading page rather than a tool.

Guides by What You Are Actually Doing

Flat card lists make you read thirteen summaries to find one page. These five routes are ordered by the mistake each guide exists to prevent.

1. You have a tape measure and a room. Start with Square Footage with Inches — it handles the feet-and-inches reading, the fraction-to-decimal step, and the survey-foot trap. Then How to Calculate Square Feet for shape by shape, and the formula table when the room has more than four sides.
2. You are buying floor covering. Measure for Flooring covers the waste range and the subfloor gate; Square Feet vs Linear Feet covers why the plank you ordered by name is not the plank that shipped; Laminate vs Vinyl vs Hardwood explains why two published "per square foot" prices for the same board differ by 2.5×.
3. You are buying by the load or the slab. Square Feet vs Cubic Feet is the volume guide — mulch, concrete, and room volume for airflow.
4. You are budgeting a build. Cost per Square Foot to Build a House reconciles the Census figure against the trade press and shows the median-versus-mean substitution that inflates most tables.
5. You are reading a listing or an appraisal. Price per Square Foot is about the denominator — what got measured — and Average Room Sizes is about why your room totals never add up to the advertised floor area.

The Whole Calculator Library, In One Place

Every calculator page on this site is linked below — 27 tools plus 7 shape-specific variants. If a tool is missing here, tell us and we will fix the index rather than the excuse.

Measure a room or a shape

• Square Footage Calculator — seven shapes, per-field units, waste and boxes.
• Fast SqFt Calculator — rectangle only, no choices to make.
• Shape pages: Room · Circle · Triangle · Trapezoid · L-Shape · Irregular · Multiple Rooms.
• Room Size Index — 61 common dimensions with the answers already computed.

Convert between units

• Down: to sq yards · to sq meters · to sq inches · to sq miles · to acres · to hectares.
• Back up: sq yards · sq meters · sq inches · sq miles · acres · hectares.
• Different dimension: sq ft to linear feet (needs a width) · sq ft to cubic feet (needs a depth).

Buy material for a project

• Flooring · Tile · Carpet · Paint · Roof · Wall · Construction.

Size and price a property

• House Square Footage · Home Size · Property Size · Cost per Square Foot.

How a Guide Gets Written and Re-Checked

Not a five-stage promise — a measurable process, with its current coverage rates from the table above.

1. Read the first page of results. Three or more published pages for the same query are fetched in full and saved. Nothing is quoted from a search snippet.
2. Look for the gap. The guide has to answer something those pages do not, or correct something they get wrong. A page that only restates length × width does not ship.
3. Re-derive every number. Percentages, unit conversions and totals on our pages are recomputed from the figures printed beside them, including our own calculator's behavior, which is checked by running its code rather than by trusting its description.
4. Quarantine what cannot be sourced. If a claim needs a document we could not fetch — a paywalled standard, a bot-blocked page — the claim comes out and the page says so. Four guides publish that list; the linear-feet guide names the ANSI webstore that answered HTTP 403 and the NIST Handbook 44 landing page that answered 404, and states plainly that it makes no claim from either.
5. Stamp and re-measure. The page's date is the date of that re-check, in visible text and in dateModified together. Ten of the eleven pages carry a worked example — the printable sheet derives its numbers column by column instead — five carry an explicit mistakes or pitfalls section, seven open with key findings, and all eleven end with a source list.

Found an error? Email [email protected] with the page and the figure. We do not promise a turnaround time, because we have no queue that would let us measure one — the verifiable signal is the page's dateModified, which moves the day a correction ships.

Site Inventory, Reconciled

Index pages are where counts usually stop adding up. Here is ours, against sitemap.xml as it stood on October 13, 2026 — 115 URLs, and the sections sum to 115 exactly.

Machine-readable entry points, if you would rather parse than scroll: llms.txt, /ai/ (Markdown of each page), and sitemap.xml. The structured data on this page declares all eleven members in hasPart; a hub that names nothing it collects is indistinguishable from a plain web page.

Frequently Asked Questions

Sources and How to Check This Page

Every figure on this index is either (a) a count taken from a file inside this repository, reproducible with the command shown, or (b) a quotation from a document fetched on October 6, 2026. The counts were re-taken on October 13, 2026 from the built HTML, after the top-level square footage article was re-checked and rewritten. Nothing here is a memory of a search result.

• Our own pages. Word counts, distinct cited hosts, source-link counts, nofollow checks and FAQ counts were taken from the built HTML of the eleven guides, after removing <script>, <style> and inline <svg>. The chrome baseline — the words shared by every page — was measured on the 404 page: 485. Reproduce it on any page: strip tags, collapse whitespace, count space-separated tokens. The October 13 re-measurement moved one row and six of the seven summary cells: page words (45,553 to 47,210), distinct cited domains (36 to 37), source links (65 to 69), visible FAQs (73 to 75), the .gov tally (10 of 11 to 11 of 11) and the oldest review date in the footer (2026-09-25 to 2026-10-05, because the only older row was the one rewritten). The domain count moved because the square footage article's new citations include en.wikipedia.org, a host no other page in this table links.
• sitemap.xml — the 115 <loc> entries behind the inventory table. Same command: grep -c "<loc>" sitemap.xml. If the buckets ever stop summing to that number, the table is the bug report.
• schema.org, CollectionPage — https://schema.org/CollectionPage, fetched 200, 38,287 bytes. The class comment reads "Web page type: Collection page," and the inherited hasPart property is defined as "Indicates an item or CreativeWork that is part of this item, or CreativeWork (in some sense)". That second quote is why this hub enumerates its eleven members instead of only describing itself.
• schema.org, ItemList — https://schema.org/ItemList, fetched 200, 97,311 bytes: "A list of items of any sort—for example, Top 10 Movies About Weathermen, or Top 100 Party Songs. Not to be confused with HTML lists, which are often used only for formatting."
• Google Search Central, Breadcrumb structured data — developers.google.com, fetched 200, 35,824 bytes. Verbatim: "To specify breadcrumbs, define a BreadcrumbList that contains at least two ListItems," and "We recommend providing breadcrumbs that represent a typical user path to a page, instead of mirroring the URL structure." The two-step breadcrumb at the top of this page follows the first; we deliberately do not claim the second proves anything about ranking.
• NIST Handbook 44 / SP 811, Appendix B.8 — NIST Guide to the SI, Appendix B.8, fetched 200, 168,958 bytes. The row we rely on across the calculator pages: "square foot (ft²) — square meter (m²) — 9.290 304 E−02". Note the shorter path without appendix-b-conversion-factors returns 404, which is why the full URL is printed.
• U.S. Census Bureau, Characteristics of New Housing highlights — census.gov, fetched 200, 61,309 bytes, headlined "Highlights of 2025 Characteristics of New Housing" and stating "The median size of a completed single-family home was 2,142 square feet." This is the .gov pointer for the housing figures three of the eleven guides reuse; the guides cite their own copies of the same tables.
• Three competitor index pages, fetched for comparison rather than citation — a guides hub that enumerated 13 cards with CollectionPage and hasPart but carried no date string anywhere in its HTML; a calculator portal whose ItemList declared numberOfItems: 364 while its own site description said "Access 331 free calculators across 30 categories"; and an engineering calculator library with per-category live counts and a <noscript> fallback but no CollectionPage or ItemList at all. We are not linking them: quoting their numbers is evidence for our table columns, not a recommendation of their pages, and their content was read as untrusted input.
• What we could not verify, and therefore did not claim. We publish no ranking or traffic statement for any guide, because no Google results page was readable from this environment — the SERP endpoint returned a sorry-page and the DuckDuckGo HTML and Lite endpoints each returned HTTP 202 challenge pages of 14,176 and 14,181 bytes with zero results. Two candidate comparators were never usable: a flooring-education hub returned HTTP 429 on four attempts across three user agents and through a fetch proxy, and a carpet retailer's guide connection returned HTTP 000 with no bytes. A fetch of Google's structured-data feature gallery succeeded but its body did not render into the retrieved HTML, so it supports no claim about which types Google consumes; we did not write one. And the ANSI Z765 standard itself is not quoted on this page — the guides that reference it point to the publisher's public text, not to a copy of the paywalled document.

Related

• Home — the same calculators, less reading.
• Room Size Index — 61 dimensions answered without measuring.
• About FootyCalc — who operates the site and how the formulas were sourced.
• Embed the calculator — put the rectangle tool on your own page.