About ChickenCalc
ChickenCalc is a set of 19 free, no-signup calculators for backyard chicken keepers, covering egg production, flock age, coop and run sizing, feed and cost, incubation and hatch dates, and colour genetics. Every tool runs instantly in your browser. Nothing is stored, no account is needed, and there is no app to install.
Who makes this
ChickenCalc is published by TerraTechna s. r. o., a company registered in Slovakia (IΔO 55744176, VAT SK2122081643), at Lermontovova 911/3, 811 05 Bratislava β StarΓ© Mesto. You can reach us at info@chickencalc.com.
It is built and run by a software developer, not a farmer. That is worth saying plainly, because a lot of sites in this space imply a barnyard backstory they do not have. We are not going to tell you about our flock, because we do not have one.
What we do have is a stubborn interest in getting the arithmetic right. Most of the chicken advice online buries a simple calculation inside 2,000 words of preamble, or repeats a rule of thumb without saying where it came from. These calculators exist to do the sum in one screen and show you exactly how it was worked out.
Where the numbers come from
Every calculator on this site carries a βHow we calculate itβ box directly below the tool. It states the actual formula in plain language, and it links to the sources the constants came from. Those sources are, wherever possible, university agricultural extension services: Penn State, Mississippi State, University of Minnesota, Oregon State, UGA, and the national Poultry Extension programme. These are public, non-commercial, and checkable.
If a figure is a widely-accepted range rather than a precise number, we give the range. Where keepers genuinely disagree, we say so rather than inventing a false consensus. We do not cite studies we have not read, and we do not quote statistics we cannot link to.
What these tools are not
They are planning estimates, not veterinary advice. Real birds vary by breed, age, weather, feed, and luck, and no calculator can account for a sick hen or a hard winter. If something is wrong with your flock, talk to a vet or your local extension office. Nothing here should be used to make a medication, dosage, or food-safety decision.
How we handle mistakes
We will get things wrong. When you tell us, we fix the calculator and the page rather than quietly editing the number and moving on. If a correction changes a result you might have relied on, we note it on the page.
Found an error, or think a constant is off? Email info@chickencalc.com and point at the specific figure. Corrections from people who actually keep birds are the most useful mail we get.
How the site pays for itself
ChickenCalc is free and has no paywall. It is funded by display advertising and by affiliate links to gear retailers, which means we may earn a commission if you buy something through a link here, at no extra cost to you. Advertising never sits inside a calculator, and a product recommendation never changes what a formula returns. Full details are on the disclosure page.