Hectares to Acres Converter

When you actually need this conversion

A vineyard outside Bordeaux is listed at 18 hectares, 45,000 € per hectare. The buyer is American and prices land per acre. The bank wants a total. The agronomist quotes yields in tonnes per hectare; the buyer's spreadsheet is in bushels per acre. At 2.47105 acres per hectare, those 18 ha are 44.5 acres, the asking price is 18,211 € per acre, and the total is 810,000 € either way. Same dirt, three different vocabularies, and only one of them belongs in each document.

This is the single most common land conversion on earth, because it sits on the fault line between two systems that both refuse to die. Hectares run agriculture almost everywhere: the EU, the UK, Canada, Australia, Latin America, Asia, Africa, every FAO and UN dataset, every EU subsidy claim, every carbon and forestry inventory. Acres run land in the United States: deeds, plats, zoning minimums, USDA programs, real-estate listings, and the entire county tax roll. If you buy foreign farmland, read an international yield study, size a solar site, or file a conservation claim, you will cross this line.

Understanding the two units

The hectare is a designed unit: exactly 10,000 m², a square 100 m on a side. Clean, decimal, and easy to scale — 100 hectares is exactly one square kilometre.

The acre is an inherited one. It began as the area a man with one ox could plough in a day, and it kept the awkward shape of that job: one chain (66 ft) wide by one furlong (660 ft) long, which is 43,560 square feet— a long, thin strip, not a square, because turning the ox around was the expensive part. That is why the number is 43,560 and not something memorable, and why the conversion factor is 2.47105 and not 2.5.

The mental shortcut, and what it costs you

Hectares × 2.5 is the field estimate everyone uses, and it is good enough to talk with. It runs 1.2% high. On a 2 ha smallholding that is 0.06 acres — noise. On a 400 ha estate it is the difference between 1,000 acres and the real 988.4: you have invented 11.6 acres, and at $10,000 an acre that is $116,000 of land that does not exist. Estimate with 2.5; contract with 2.47105.

Hectares to acres reference

Acres rounded to two decimals. The "what that looks like" column is the fastest way to catch an order-of-magnitude error.

Going the other way, use the acres to hectares converter. For map-scale figures try hectares to square kilometres, for building lots acres to square feet, and for US survey descriptions sections to acres.

Worked examples where the number decides something

Four scenarios, each with the arithmetic written out. In every case the conversion itself is trivial — what costs money is converting the parcel and forgetting the rate attached to it.

Worked example 1: farmland priced in two different units of area

An Iowa buyer holds row-crop ground at $11,000 per acre and is shown French vineyard at 45,000 € per hectare. Those two numbers cannot be compared as they stand. Convert: 45,000 €/ha ÷ 2.47105 = 18,211 € per acre, roughly $19,600. The vineyard is not "four times" the Iowa price, as the raw figures suggest — it is under twice. Always convert the rate, not just the area.

Worked example 2: turning an agronomy figure into a farm plan

A trial reports a maize yield of 9.5 tonnes per hectare and a nitrogen rate of 180 kg per hectare. Your fields are in acres. Divide by 2.47105: 3.84 t/acre and 72.8 kg/acre. Apply the per-hectare nitrogen rate to an acre count instead and you over-apply by 147%— expensive, agronomically wrong, and in nitrate-sensitive zones potentially a compliance problem.

Worked example 3: sizing a site against a zoning minimum

A county requires 5-acre minimum lots. Your parcel is recorded on an old metric survey as 30 hectares. That is 74.13 acres gross, which looks like 14 lots. It is not: strip out a 12% allowance for the access road, drainage, and setbacks and you are working with about 65 acres — 13 lots. One lot, decided by a rounding habit and a road you forgot to subtract.

Worked example 4: checking a renewable-energy site against a metric land offer

A developer sizes utility-scale solar with an internal rule of thumb of 5 acres per MW of AC capacity, and is offered a 60-hectare block by a European landowner. Convert first: 60 × 2.47105 = 148.26 acres, which under that rule supports roughly 29.6 MW. Estimate the same block with the 2.5 shortcut and you get 150 acres and 30 MW — a tidy round number that tempts you to size the interconnection request at 30 MW on land that only carries 29.6. The conversion did not cost you anything here; the rounding did. Convert at full precision, then apply the rule of thumb, then round the answer — never the reverse.

Checklist before you trust the number

• Check the direction. Hectares → acres gets bigger(× 2.47). Acres → hectares gets smaller(× 0.40). If a 10-hectare farm converts to 4 acres, you ran it backwards.
• Convert the rates too. Yield, seed, fertiliser, spray, subsidy, and price are all quoted per unit area. Converting the parcel but leaving the rate in per-hectare terms is the most expensive mistake on this page.
• Use 2.47105, not 2.5, once money is involved.The 2.5 shortcut is 1.2% high — fine for conversation, wrong for a contract.
• Separate gross from net. Deeds record total parcel area. Roads, ditches, headlands, buildings, wetlands, and setbacks all come out of what you can actually farm or build on.
• Watch for the Irish and Scottish acre in historic documents. The Irish acre is about 1.62 statute acres; the Scottish acre about 1.27. Both were abolished long ago, but they still sit in old deeds.
• Sanity-check the magnitude. A suburban lot is a fraction of a hectare. If your conversion says the back garden is 40 acres, you multiplied where you should have divided.
• Round only at the end.Convert at full precision, then round for the report — not the other way around.

Accuracy, privacy, and limits

What is exact

Both units are exactly defined, so the factor is not an estimate. The hectare is exactly 10,000 m². The international acre is exactly 43,560 ft² on a foot defined as exactly 0.3048 m, which makes it 4,046.8564224 m² exactly. Divide and you get 2.4710538...acres per hectare — an endless decimal, but a fully determined one. This converter uses 2.47105, accurate to about 1.5 parts per million: on a 1,000-hectare holding, an error of roughly 0.004 acres.

What is not the maths

The soft part is the area itself, not the conversion. The area on a title is not the area on the ground.Historic surveys drift, boundaries move, rivers migrate, and a modern GPS re-survey commonly returns a figure a few percent off the recorded one — a gap far larger than any rounding here. One footnote for US documents: land described under the old US survey foot yields an acre about 4 parts per million different from the international acre. That distinction was retired at the end of 2022 and it will never matter to you, but it is why two authoritative sources can print slightly different digits.

This is not legal, tax, or survey advice

A converted figure is for orientation, comparison, and budgeting. It does not replace the area recorded in the deed, plat, or cadastre, which is what governs property tax, transfer tax, subsidy eligibility, zoning compliance, and any boundary dispute. For anything binding, work from a licensed surveyor's measurement and the official record.

Privacy and local processing

This converter runs entirely in your browser. The parcel sizes you type stay on your device — nothing is sent to a server, logged, or stored, and there is no account to create. Once the page has loaded it keeps working offline, so nothing about the land you are researching or the deal you are negotiating leaves your machine.

Frequently asked questions

The questions below are the ones that actually change an answer — direction, precision, per-unit rates, and which figure a registry will accept.