Hens and eggs calculator
How many hens do I need for the eggs I want, and how many eggs will my hens lay?
Showing for United States
Hens you need
—
- Eggs a week
- —
- Spare eggs a week
- —
- Dozens a week
- —
The lay rate is the share of your hens that lays on an average day across the whole period, so it already takes in days off lay and hens that stop. Your own egg records are the best source.
For comparison only, not a default: one University of Maryland Extension budget for a backyard flock (2026) assumes 70% a day over three years, with hens that die counted in and extra light in winter. Your own records are better.
Hens are whole, so the flock can lay a few more eggs than you asked for.
This calculator counts eggs. For what a dozen costs you to produce, use the egg cost calculator.
Eggs a week
—
- Dozens a week
- —
- Eggs a day
- —
The lay rate is the share of your hens that lays on an average day across the whole period, so it already takes in days off lay and hens that stop. Your own egg records are the best source.
For comparison only, not a default: one University of Maryland Extension budget for a backyard flock (2026) assumes 70% a day over three years, with hens that die counted in and extra light in winter. Your own records are better.
Eggs are averages over many days, rounded to whole eggs a week. A single week can be more or less.
This calculator counts eggs. For what a dozen costs you to produce, use the egg cost calculator.
Eggs a week in winter
—
- Eggs a week the rest of the year
- —
- Fewer eggs a week in winter
- —
- Dozens a week in winter
- —
- Winter drop
- —
- Hens you need for those eggs in winter
- —
The lay rate is the share of your hens that lays on an average day across the whole period, so it already takes in days off lay and hens that stop. Your own egg records are the best source.
Enter the share of your hens that lays on an average winter day, from your own records. It cannot be higher than your usual rate.
Hens are whole, so the flock can lay a few more eggs than you asked for.
This calculator counts eggs. For what a dozen costs you to produce, use the egg cost calculator.
Enter your numbers to see the result.
Planning a farm stand, a CSA or a shop? TallyTill is free to start.
Get started with TallyTill for freeUse this calculator in an AI chat
You can ask Claude, ChatGPT or another AI app to work this out for you, and this calculator opens right inside the chat. You connect TallyTill to your AI app once. It is free, and there is no account and no sign-in.
AI apps call add-ons like this connectors, apps or MCP servers. They all mean the same thing: a way for the AI to use a tool someone else made.
1. Copy this address
2. Add it to your AI app
Claude (claude.ai and the Claude desktop app)
- Open Customize, then Connectors.
- Press + Add, then Add custom connector.
- Name it TallyTill calculators, paste the address and press Continue.
- Under Authentication choose No sign in, then press Add.
- In a new chat, press + at the bottom left, choose Connectors and switch TallyTill calculators on.
On Claude's free plan you can add one custom connector.
ChatGPT
- In Settings, turn on Developer mode. OpenAI moves this switch from time to time; it is usually with the settings for apps and connectors.
- Add a new connector (ChatGPT may call it an app), paste the address and choose No authentication.
- In a new chat, choose TallyTill from the tools menu, or type @ and pick it.
Not every ChatGPT plan lets you add your own connector. If you cannot find the option, your plan may not include it.
Using another AI app? Look in its settings for MCP, add the address as a remote server, and choose no sign-in.
3. Ask your question
Say "use TallyTill", so the AI uses the calculator instead of doing the sum itself. For example:
"Use TallyTill: How many hens do I need for the eggs I want, and how many eggs will my hens lay?"
What you will see
- The calculator opens in the chat with the numbers you gave already filled in. Change any number and the answer updates.
- If a number is missing, the box is highlighted, or the AI asks you for it in plain words.
- The answer links back to this page, so you can check the working.
- The first time, your AI app asks if it may use TallyTill. Choose Allow.
The calculators take numbers only. They never ask for your name, your email or a password.
How this is worked out
One hen lays 7 times your lay rate, divided by 100, eggs a week. The hens you need are the eggs you want each week divided by that, rounded up to a whole hen. A flock lays its hens times 7 times the lay rate, divided by 100, eggs a week, shown to the nearest egg; a dozen is 12 eggs. The winter drop is the same sum at your winter lay rate, and the drop in percent is the difference between the two rates divided by the usual rate.
A worked example
Example numbers only; use your own. If 70 percent of your hens lay on an average day, one hen gives 4.9 eggs a week, so 24 eggs a week takes 5 hens, which lay about 25. Six hens at that rate lay about 29 eggs a week, or 2.5 dozen. If only 35 percent lay on a winter day, those six hens lay about 15 eggs a week in winter, 14 fewer, and 24 eggs a week would then take 10 hens.
Nothing you type here is saved.