About HatchMath

HatchMath is a small set of calculators and short reference pages for people keeping chickens in their backyard. The numbers come from USDA bulletins, Cooperative Extension Service publications, and ATTRA technical notes — the same kinds of documents county extension agents hand out at the feed store. Where the published guidance gives a range, the calculator shows the range.

What this site is

• Free calculators for the questions a small flock keeper actually runs into: coop square footage, run space, feed quantity by age class, layer feed conversion, brooder heat, ventilation area.
• Short methodology notes attached to each calculator. Formula, where it comes from, what it assumes, and what it cannot account for.
• A glossary of the working terms — square feet per bird, lumens per square foot, ppm of ammonia — cross-linked into the calculators so a definition is one click away.

Why this site exists

Most chicken-keeping content online is a blog post wrapped around a banner ad, with a calculator wedged in if there's room. HatchMath is built the other way around. The calculator is the page. The text supports it. If a paragraph isn't helping you read the result or check an assumption, it doesn't ship.

The other reason: the published agricultural-extension literature on small flocks is genuinely good and genuinely free. Land-grant universities have been writing it for a hundred years. Most backyard keepers never see it because it lives in PDFs nobody links to. Pulling those numbers into calculators is a useful thing to do.

What this site isn't

• Not a veterinary resource. Sick birds, parasite questions, and disease diagnosis go to an avian or livestock vet, or your county Cooperative Extension office. We link out where it makes sense.
• Not a breed-shopping guide.We don't tell you which breed to buy. Temperament and lay rates vary inside any breed, and the published numbers for “X eggs per year” are advertising more often than data.
• Not anti-vaccine, not anti-conventional-ag. Marek's vaccination at the hatchery is a settled question. Commercial feed mills produce safe, well-formulated feed. We treat both as the baseline and discuss alternatives where the evidence supports them.

Author

Jimmy L Wuwrites HatchMath. The framing on every page: calculator first, sourced math second, range-based answers third. Where the published extension guidance gives a number, the calculator surfaces it. Where HatchMath synthesizes practitioner consensus into a number that isn't directly published, the page labels it HatchMath methodology — visibly, in both the calculator UI and the methodology page.

Sourcing and contact

For how claims are sourced and verified, see the editorial policy. For the formula and assumption list behind any calculator, see methodology. For monetization, see disclosures.

Questions, corrections, broken links: admin@hatchmath.com.