Formula
Hectares = acres × 0.40468564224. Square metres = hectares × 10,000. Square feet = acres × 43,560. Optional planning hectares = hectares × (1 + allowance percent ÷ 100).
CalculationTime
To calculate time is to make the future less invisible.
Worked example
For 25 acres: 25 × 0.40468564224 = 10.117141056 hectares. The same land area is 101,171.41056 square metres and 1,089,000 square feet. With a 5% planning allowance, the note would show 10.623 hectares for rough planning, while the measured area remains 10.117 hectares.
Professional note
Master’s Tip: print both the original acres and converted hectares. Land records, farm plans and property listings often move between systems, and the original unit is the audit trail.
Regional and unit assumptions
Uses international acre and SI hectare conversion arithmetic. This page is for unit conversion and planning records, not boundary surveying, legal title interpretation or land valuation.
Assumptions and limitations
- The acre is treated as the international acre of 43,560 square feet.
- One hectare is 10,000 square metres.
- The conversion factor used is 1 acre = 0.40468564224 hectares.
- Any allowance is a planning note only and must not replace surveyed, title, cadastral or legal land area.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Hectares = acres × 0.40468564224. Square metres = hectares × 10,000. Square feet = acres × 43,560. Optional planning hectares = hectares × (1 + allowance percent ÷ 100).
Standard or basis
Uses international acre and SI hectare conversion arithmetic. This page is for unit conversion and planning records, not boundary surveying, legal title interpretation or land valuation.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: print both the original acres and converted hectares. Land records, farm plans and property listings often move between systems, and the original unit is the audit trail.
Related calculators
Questions
How many hectares are in one acre?
One acre equals 0.40468564224 hectares.
How do I convert acres to hectares?
Multiply the acre value by 0.40468564224. For example, 25 acres × 0.40468564224 = 10.1171 hectares.
Is a hectare bigger than an acre?
Yes. One hectare is about 2.47105 acres, so a hectare is larger than an acre.
Can I use this for property records?
Use it as an arithmetic conversion record only. Legal property area should come from the survey, title, cadastral record or local authority source.
Why does the printable report keep acres and hectares?
Keeping both units makes the record easier to verify later, especially when a quote, farm plan, classroom worksheet or property note is shared across metric and imperial users.
Calculation note
Acres and hectares come from different measurement traditions. The acre is common in land and property records in countries that still use imperial or customary units, while the hectare is a metric land-area unit equal to 10,000 square metres. A good conversion record preserves both units instead of silently replacing one with the other.
The acre is a land-area unit
In modern conversion tables, the international acre is defined as 43,560 square feet. That makes it convenient for property and farm records that still use feet, yards and miles, but it can be awkward when plans, maps or materials are specified in metric units.
The hectare is built from square metres
A hectare is 10,000 square metres, equivalent to a square 100 metres on each side. That direct link to the metre is why hectares are useful for maps, agricultural areas, environmental records and metric planning documents.
Why the original unit should stay visible
Land-area conversions are often copied into quotes, listings, farm notes and classroom worksheets. The printable report keeps acres, hectares, square metres and square feet together so a later reader can see the source unit, the formula and any optional planning allowance.
Sources and further readingNIST Handbook 44 Appendix C: General tables of units of measurementBIPM: SI Brochure