Field area calculator and acre converter
How many acres is my field, and what is that in hectares?
Showing for United States
Acres
—
- Hectares
- —
- Square feet
- —
- Square meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
For a field that is not one simple shape, split it into rectangles and triangles, work out each one and add them up.
This uses the measurements you take. For a boundary, a sale or a lease, a surveyor's figure is the one that counts.
Acres
—
- Hectares
- —
- Square feet
- —
- Square meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
For a field that is not one simple shape, split it into rectangles and triangles, work out each one and add them up.
This uses the measurements you take. For a boundary, a sale or a lease, a surveyor's figure is the one that counts.
Acres
—
- Hectares
- —
- Square feet
- —
- Square meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
For a field that is not one simple shape, split it into rectangles and triangles, work out each one and add them up.
This uses the measurements you take. For a boundary, a sale or a lease, a surveyor's figure is the one that counts.
Acres
—
- Hectares
- —
- Square feet
- —
- Square meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
For a field that is not one simple shape, split it into rectangles and triangles, work out each one and add them up.
This uses the measurements you take. For a boundary, a sale or a lease, a surveyor's figure is the one that counts.
Acres
—
- Hectares
- —
- Square feet
- —
- Square meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
US gallons
—
- Acre-inches
- —
- Imperial (UK) gallons
- —
- Liters
- —
- Cubic meters
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
A US gallon (3.785 liters) is smaller than an imperial or UK gallon (4.546 liters). Check which one your figure uses.
US gallons per acre
—
- Liters per hectare
- —
- Imperial (UK) gallons per acre
- —
Conversions use the exact definitions: a foot is 0.3048 m, an acre 43,560 square feet, a hectare 10,000 m², a US gallon 3.785411784 liters and an imperial gallon 4.54609 liters.
A US gallon (3.785 liters) is smaller than an imperial or UK gallon (4.546 liters). Check which one your figure uses.
Enter your numbers to see the result.
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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 acres is my field, and what is that in hectares?"
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
A rectangle is length times width; a triangle is half its base times its height, measured square to the base; a trapezoid is the average of its two parallel sides times the distance between them; a circle is π times the radius squared. Conversions use the exact definitions: a foot is 0.3048 m, a yard 0.9144 m, an acre 43,560 square feet (4,046.8564224 m²), a hectare 10,000 m², an acre-inch 6,272,640 cubic inches (102,790.15 liters), a US gallon 231 cubic inches (3.785411784 liters) and an imperial gallon 4.54609 liters. Each figure is rounded once, where it is shown.
A worked example
Example numbers only; use your own. A field 500 ft long and 36 ft wide, University of Georgia Extension's example, is 18,000 square feet: 0.4132 acres. A center pivot 1,320 ft long waters a circle of 125.6637 acres. One acre-inch of water is 27,154.29 US gallons, and 20 US gallons per acre is 187.08 liters per hectare.
Nothing you type here is saved.