Acres to Square Meters Converter — Convert acres to m² (Exact: 1 acre = 4,046.8564224 m²)
Accurate acres (ac) to square meters (m²) converter using the exact international definition 1 acre = 4,046.8564224 m². Purpose-built for land records, real estate, agriculture, surveying, GIS, conservation, and planning. Includes precise formulas, worked examples, expanded reference tables, rounding guidance, detailed FAQs, and practical tips.
Exact factor: 1 acre = 4,046.8564224 m² ⇒ m² = acres × 4,046.8564224. See all agricultural land area converters.
About Acres to Square Meters Conversion
The acre (ac) remains common in the U.S., UK, and parts of the Commonwealth for land transactions, listings, and agricultural parcels. The square meter (m²) is the SI foundation underneath GIS, engineering, and environmental reporting. Converting acres to square meters lets you keep precise analytics in SI while presenting familiar acre values to stakeholders.
Since 1 acre = 4,046.8564224 m² exactly (international acre), the conversion is clean and reproducible across spreadsheets, APIs, and maps. A robust practice is to store areas in m² (or hectares), perform joins and rollups there, and round once at presentation when rendering acres for public or client-facing materials. That single rounding step prevents subtle discrepancies between PDFs, emails, and dashboards.
Typical workflows include parcel polygons computed in m² within GIS, then surfaced as acres in a real estate brochure, or agricultural field boundaries maintained in hectares and displayed as acres for U.S. partners. By documenting constants and rounding policy, teams avoid rework and audit disputes.
Acres to Square Meters Formula
Exact relationship
Use either expression:
m² = acres × 4,046.8564224
// inverse
acres = m² ÷ 4,046.8564224Example:
2.5 acres × 4,046.8564224 = 10,117.141056 m²Related Area Converters
What is an Acre (ac)?
An acre is a customary land area unit historically tied to survey systems. In its international form it is exactly 4,046.8564224 m². It remains prevalent in listings, deeds, and agricultural contexts in the U.S. and UK. For large-scale summaries, acres are often translated to hectares or km² to keep numbers compact.
What is a Square Meter (m²)?
The square meter is the SI unit of area—the area of a square one meter per side. It underpins engineering, construction, GIS analytics, and environmental metrics. For parcels and fields, hectares (10,000 m²) provide a readable summary, but m² remains the canonical unit for precise computation and data storage.
Step-by-Step: Converting acres to m²
- Read the area in acres (ac) from the deed, listing, or GIS attribute.
- Multiply by 4,046.8564224 to convert to square meters (m²).
- Round once at presentation (e.g., whole m² for simple summaries; more precision for technical annexes).
Example walkthrough:
Input: 0.84 ac
Compute: 0.84 × 4,046.8564224 = 3,399.357392896 m²
Output: 3,399.36 m² (UI policy: 2 decimals; keep full precision internally)Common Conversions
Everyday quick checks (acres → m²)
| acres | m² | acres | m² |
|---|---|---|---|
| 0.10 | 404.68564224 | 0.50 | 2,023.42821120 |
| 0.75 | 3,035.14231680 | 1.00 | 4,046.85642240 |
| 1.50 | 6,070.28463360 | 2.00 | 8,093.71284480 |
| 5.00 | 20,234.28211200 | 10.00 | 40,468.56422400 |
| 25.00 | 101,171.41056000 | 100.00 | 404,685.64224000 |
Quick Reference Table
Square meters to acres (m² → acres)
| m² | acres | m² | acres |
|---|---|---|---|
| 404.68564224 | 0.10 | 2,023.42821120 | 0.50 |
| 3,035.14231680 | 0.75 | 4,046.85642240 | 1.00 |
| 6,070.28463360 | 1.50 | 8,093.71284480 | 2.00 |
| 20,234.28211200 | 5.00 | 40,468.56422400 | 10.00 |
| 101,171.41056000 | 25.00 | 404,685.64224000 | 100.00 |
Precision, Rounding & Significant Figures
Operational rounding
Public dashboards typically show acres to two decimals or whole m² for readability. Engineering annexes might display more digits aligned with measurement quality. Whatever you choose, compute with full precision internally and round once on output to keep every surface synchronized.
Consistent documentation
Standardize field names (e.g., area_m2, area_ac) and add a methods note: “Exact: 1 acre = 4,046.8564224 m²; round once at presentation.” Consistency across teams and vendors prevents small discrepancies from compounding in audits.
Where This Converter Is Used
- 🏠 Real estate & listings: Parcel areas presented in acres while CAD/GIS stores m² or ha.
- 🌾 Agriculture: Field boundaries analyzed in m²/ha and translated to acres for U.S. partners.
- 🗺️ GIS & planning: Geometries computed in m², summarized as acres for public engagement.
- 🌳 Forestry & conservation: Stand and habitat extents converted between acres and m²/ha for reports.
- 🏛️ Permitting & compliance: Forms that accept acres while internal systems use SI units.
Frequently Asked Questions
What is the exact formula to convert acres to square meters?
Use the international acre: 1 acre = 4,046.8564224 m² (exact). Therefore m² = acres × 4,046.8564224. The inverse is acres = m² ÷ 4,046.8564224. Because the constants derive from exact SI definitions (1 yd = 0.9144 m, 1 acre = 4,840 yd²), these conversions are audit-safe across CAD, GIS, and government forms.
Are all acres the same? What about the US survey acre?
This tool uses the international acre (exactly 4,046.8564224 m²), now standard in most contexts. A US survey acre is based on the US survey foot and differs by a few parts per million—irrelevant for most real-estate and planning work but potentially material in geodetic surveys. If your project mandates survey foot units, document that choice and apply a survey-based factor consistently.
Should I store land areas in acres or square meters?
Pick a single canonical storage unit—many teams use m² or hectares (ha)—and convert to acres for user-facing displays. Centralizing on SI simplifies joins, geometry operations, and cross-border reporting. Convert at the edges and round once on output to keep PDFs, emails, and exports in perfect agreement.
How should I round for public dashboards, deeds, and permits?
Compute with full precision, then round only when presenting. Headlines often show whole m² or two decimals in acres; technical annexes may keep more digits. Publish a short rounding policy so templates, PDFs, and CSVs match across departments and vendors.
Do map projections or geodesic methods change the acre ↔ m² factor?
No. The conversion factor is a unit definition. Projection/geodesic choices affect how you calculate an area from geometry, not how you convert between units. Once you have an area in acres or m², the conversion always uses the fixed constants shown above.
How do acres relate to hectares and square kilometers?
1 hectare = 10,000 m² ≈ 2.47105381 acres. Therefore 1 acre ≈ 0.404685642 ha. For large extents: 1 km² = 1,000,000 m² ≈ 247.105381 acres. Keep one canonical unit (often m²) and derive the others for display and reporting.
What field names and documentation help prevent unit mistakes?
Use explicit, unit-suffixed fields such as area_m2 and area_ac. Add a methods note: “Exact constants: 1 acre = 4,046.8564224 m²; round once at presentation.” Clear naming plus a single rounding policy eliminates double-conversion errors and audit drift.
What anchor values help me sanity-check conversions quickly?
Memorize: 1 ac = 4,046.8564224 m²; 0.5 ac = 2,023.4282112 m²; 2 ac = 8,093.7128448 m². Conversely, 10,000 m² ≈ 2.47105 ac. These make great mental checks and regression test pairs in spreadsheets or CI.
Tips for Working with acres & m²
- Keep m² canonical for computation; derive acres for U.S.-facing interfaces.
- Round once at output and apply the same rule across dashboards, PDFs, and CSV exports.
- Use explicit unit-suffixed fields (area_m2, area_ac) and publish constants in your methods note.
- Maintain a regression set (e.g., 1 ac ↔ 4,046.8564224 m²; 2.5 ac ↔ 10,117.141056 m²) and assert both directions in tests.