Area Converter

How Area Converter Works

result = value × (factor_from ÷ factor_to)

m²

Square Meter — The SI unit of area. The area of a square measuring one meter on each side. Used worldwide for room sizes, construction, and land measurement. A typical parking space is about 12.5 m² (2.5 m × 5 m).

ft²

Square Foot — The US customary unit of area. The area of a square measuring one foot on each side (144 in²). Used for real estate, construction, and HVAC in the US. A typical American house is 1,500-2,500 ft².

ac

Acre — The traditional US/UK land unit: exactly 43,560 ft² = 4,046.86 m² = 0.404686 ha. Originally the area a yoke of oxen could plow in one day. Still used for US real estate, agriculture, and land surveying.

ha

Hectare — The metric land unit: exactly 10,000 m² = 100 m × 100 m = 2.471 acres. Used worldwide for agriculture, forestry, and land management. Roughly the size of a rugby pitch or international soccer field.

km²

Square Kilometer — One million square meters (1,000 m × 1,000 m). Used for city sizes, national parks, and country areas. Manhattan is 59.1 km². The smallest country, Vatican City, is 0.44 km².

mi²

Square Mile — Exactly 640 acres = 2.59 km². Used for large land areas in the US. A US "township" in the PLSS is 36 mi² (6 mi × 6 mi), divided into 36 sections of 1 mi² each.

Source: The square meter (m²) was adopted by the CGPM in 1960 as the SI derived unit of area. The acre was standardized by Edward I of England in the 14th century (Statute for Measuring Land) as 4 rods × 40 rods (66 ft × 660 ft = 43,560 ft²). The hectare was introduced in France in 1795 as part of the metric system as 100 ares, where 1 are = 100 m². The international foot (1959) fixed the relationship 1 ft = 0.3048 m exactly, thereby fixing 1 ft² = 0.09290304 m² and all derived area units. The square mile (1 mi² = 640 acres) was fundamental to the US Public Land Survey System (PLSS) established by the Land Ordinance of 1785.

How to Use

1. Enter the area value you want to convert in the "Value" field (e.g., 1500 for 1,500 ft² or 10 for 10 hectares).
2. Select the current area unit from the "From" dropdown — choose from m², ft², acres, hectares, km², mi², and more.
3. Select the desired area unit from the "To" dropdown — the target unit for your calculation.
4. The converted value appears instantly with the mathematical formula. Use the quick reference table to verify common area conversions.

Quick Reference

Common Uses

• •Real estate: converting between m² and ft² for property listings when comparing homes across countries (a 200 m² apartment = ~2,153 ft²)
• •Construction: calculating floor area, wall area, roofing area, and flooring material quantities in m² or ft² — knowing both units prevents ordering errors with international suppliers
• •Land measurement: converting between acres, hectares, and square miles for farms, development parcels, and conservation land — USDA reports in acres, FAO uses hectares
• •Geography: comparing country and city sizes in km² or mi² — Russia is 17.1 million km², the US is 9.83 million km², and the EU is 4.23 million km²
• •HVAC engineering: sizing heating and cooling systems based on floor area — US Manual J calculations use ft², European standards use m²
• •Agriculture: crop yield is measured in bushels/acre (US) or tonnes/hectare (metric), requiring both area unit and weight unit conversion for international commodity trading

Understanding the Result

Worked Examples

Frequently Asked Questions

How do I quickly convert between square meters and square feet?

Multiply m² by 10.764 to get ft². Multiply ft² by 0.0929 to get m². For rough mental estimation: 1 m² ≈ 10.8 ft². A 100 m² apartment ≈ 1,076 ft². A 2,000 ft² house ≈ 186 m². Important: do NOT use the same conversion factor as linear feet-to-meters (3.28) — area factors must be squared. The exact factor 10.76391 comes from (1 meter / 0.3048)², as 1 international foot = 0.3048 m exactly since 1959. For land: 1 acre = 4,046.86 m² ≈ 0.405 ha. 1 hectare = 2.471 acres.

Why does the US use acres instead of hectares?

The acre has been used in English-speaking countries since the Middle Ages. It was standardized as 43,560 ft² by Edward I in the late 13th century in the Statute for Measuring Land. The US inherited the acre from British colonial practice and embedded it deeply into the Public Land Survey System of 1785, which divided the western US into townships (36 mi²) and sections (1 mi² = 640 acres). This grid became the basis for all US land ownership, with property deeds referencing aliquot parts of sections (e.g., "the NW quarter of the SE quarter of Section 15"). Changing to hectares would require re-surveying the entire country. While the UK officially adopted the hectare for land registration in 1985, the US has not followed — and given the PLSS legacy, likely never will. The acre persists in US real estate, agriculture (USDA reports), and land management (National Park Service, BLM).

How is area measured for irregular-shaped properties?

For irregular properties, surveyors use coordinate geometry. The property boundary is surveyed as a series of vertices (corners) with precise GPS or total station measurements, and the area is calculated using the Shoelace formula (also called the surveyor's formula). This formula works for any simple polygon: Area = ½ |Σ(xᵢyᵢ₊₁ − xᵢ₊₁yᵢ)|. Modern GIS software and CAD programs can also calculate areas from satellite imagery or digital maps. For practical real estate purposes, listings often use approximate rectangular dimensions (e.g., "100 ft × 150 ft lot"), but the legal property description in the deed is based on the surveyed boundary. For curved boundaries, approximations using many short line segments are used. The accuracy of property surveys is typically ±0.1 ft + 50 ppm of the distance measured.

What is the difference between gross area, net area, and livable area?

Gross Floor Area (GFA) includes everything within the exterior walls: all rooms, hallways, closets, staircases, wall thicknesses, and mechanical spaces. Net Internal Area (NIA) excludes walls, columns, elevators, and common areas. Living Area (or finished area) excludes garages, basements (unless finished), attics, and unheated spaces. Different countries and purposes use different standards: US residential listings use "finished living area" per ANSI Z765. US commercial uses BOMA standards (Gross Leasable Area). The UK uses RICS standards (Net Internal Area for residential, Gross Internal Area for commercial). Europe uses various national standards, typically "usable floor area" (Wohnfläche in Germany, superficie utile in France). This means a 2,000 ft² US house might be advertised as 170 m² in Europe (not 186 m² as the raw math suggests) due to different measurement inclusion rules.

How many acres is a typical farm, and how does that compare globally?

US average farm size: 446 acres (180 ha) as of 2023, though this varies enormously — a small family farm might be 50-200 acres while a large corporate grain operation can be 5,000+ acres. By global comparison: average farm size in India is about 2.7 acres (1.1 ha), in Brazil about 158 acres (64 ha), in the UK about 210 acres (85 ha), and in Australia about 10,700 acres (4,331 ha) due to extensive sheep and cattle stations. Iowa farms average about 359 acres (145 ha) while Montana farms average 2,157 acres (873 ha). The largest single farm in the world is the Mudanjiang City Mega Farm in China at 22.5 million acres (9.1 million ha) — roughly the size of Portugal.

How do I calculate carpet or flooring area from room dimensions?

Multiply room length × width in consistent units (feet or meters), then sum all rooms. Add 5-10% for waste (cutting and pattern matching). Convert the total to the unit your flooring is sold in: US flooring is sold by the ft² or yd² (1 yd² = 9 ft²), while metric flooring is sold by the m². Example: a 12 ft × 15 ft living room = 180 ft², with 10% waste = 198 ft². In m²: the same room is 3.66 m × 4.57 m = 16.7 m², plus 10% = 18.4 m². For stairs, measure each tread and riser separately — stairs typically add 20-30% to the floor area of the room they connect. Always buy an extra box — dye lots change between production runs.

Pro Tips

• →For real estate comparisons: 1 m² ≈ 10.764 ft². The quick mental math is: m² × 10.76 = ft² (or roughly m² × 11, then subtract 2%). A 100 m² apartment ≈ 1,076 ft². The reverse: ft² ÷ 10.764 = m² (or roughly divide by 11 and add a bit).
• →When buying land in the US, always convert acres to a recognizable measure: 1 acre = 43,560 ft² — roughly a football field without the end zones (a football field is 57,600 ft² including end zones). An acre is about 209 ft × 209 ft, or a square about 63.6 m per side. A "40-acre" farm is a 1/16 section square roughly 1/4 mile per side.
• →For roofing estimates: roofers quote in "squares" (1 square = 100 ft² = 9.29 m²). When converting from the house floor area, remember the roof area is larger due to pitch. A 30° roof pitch adds about 15% area. Always get the actual roof dimensions rather than estimating from floor area alone.
• →When reading international construction specs: US rebar spacing is in inches, concrete volume in cubic yards (1 yd³ = 27 ft³), and formwork in ft². European specs are all metric. A common error is converting the area but forgetting the thickness when computing volume — double-check your dimensional analysis.
• →For gardens and landscaping: soil, mulch, and gravel are sold by the cubic yard in the US (1 yd³ covers ~100 ft² at 3" depth), but by the cubic meter in metric countries (1 m³ covers ~10 m² at 10 cm depth). The area converter handles the m²↔ft² step, but you will need a separate volume calculation for material quantities.
• →Use the "acre foot" concept for large-scale water management: 1 acre-foot = the water volume covering 1 acre to a depth of 1 foot = 43,560 ft³ = 325,851 gallons = 1,233.5 m³. This is the standard unit for reservoir capacity, irrigation water rights, and annual water consumption in the Western US.

Limitations to Know

• •This calculator performs linear unit conversion for area only. It does not calculate the area of irregular shapes — you need survey data or a planimeter for that. For rectangular areas, multiply length × width in consistent units first, then convert the result.
• •Area unit conversion involves squared conversion factors. When converting linear units to area units: 1 m = 3.28084 ft, but 1 m² = 10.7639 ft² (not 3.28084 ft²). The factor is squared. This calculator handles this correctly through the factor system, but be careful when doing mental conversions — squaring errors are the most common area conversion mistake.
• •Real estate "area" definitions vary by country and purpose: Gross Floor Area (GFA), Net Internal Area (NIA), Gross Leasable Area (GLA), and living area all measure different things. US listings typically use "finished living area" which excludes garages, basements, and unfinished spaces. European listings may use "usable floor area" which differs from US definitions. This converter handles the units, not the measurement methodology.
• •For agricultural land, "arable acres" may differ from "total acres" due to ponds, woodlots, buildings, and roads. When converting farm sizes for crop planning, use the actual cultivable area, not the deed acreage. Similarly, land slope means the surface area is larger than the map (planar) area — a 30° slope increases surface area by about 15%.
• •Square mile and square kilometer conversions at very large scales (state, country) use the same factors but may have rounding differences from official statistics due to coastline paradox effects (coastline length depends on measurement scale). Official country areas from the CIA World Factbook or UN Statistics Division should be used for formal comparisons.

Sources

• USDA - Land Measurement and Survey Standards
• RICS - Code of Measuring Practice