Area Unit Converter

Site plans, equipment footprints and pipe bores are quoted in square metres on one drawing, acres on a parcel record and square feet on an imperial panel, while a hectare means something specific to a process yard. This converter moves exactly between metric and imperial area with no approximation.

Convert area unit units

Why area units collide

Metric area is decimal (m², cm², mm², km²) while imperial area stacks square inches, feet, yards and miles on the same non-decimal length bases that already cause conversion errors. The hectare (10 000 m²) and the acre (4046.8564224 m²) are the practical land units in between.

All factors are exact definitions — 1 ft² = 0.09290304 m², 1 acre = 4046.8564224 m², 1 ha = 10 000 m² — so the converter returns exact values, not rounded ones. The only discipline is carrying the unit with the number.

Which unit where

Square metres rule piping, panel and equipment drawings; hectares and acres describe process yards, tank farms and parcels; square feet are the imperial language of structural and HVAC layouts. Convert at the boundary rather than mixing units inside one calculation.

Complete conversion reference

Convert 1 unit tom²km²cm²mm²haacreft²yd²mi²in²
1 m²11e-06100001e+060.00010.00024710510.76391.195993.86102e-071550
1 km²1e+0611e+101e+12100247.1051.07639e+071.19599e+060.3861021.55e+09
1 cm²0.00011e-1011001e-082.47105e-080.001076390.0001195993.86102e-110.155
1 mm²1e-061e-120.0111e-102.47105e-101.07639e-051.19599e-063.86102e-130.00155
1 ha100000.011e+081e+1012.4710510763911959.90.003861021.55e+07
1 acre4046.860.004046864.04686e+074.04686e+090.40468614356048400.00156256.27264e+06
1 ft²0.0929039.2903e-08929.03929039.2903e-062.29568e-0510.1111113.58701e-08144
1 yd²0.8361278.36127e-078361.278361278.36127e-050.000206612913.22831e-071296
1 mi²2.58999e+062.589992.58999e+102.58999e+12258.9996402.78784e+073.0976e+0614.01449e+09
1 in²0.000645166.4516e-106.4516645.166.4516e-081.59423e-070.006944440.0007716052.49098e-101

Instruments for this measurement

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Frequently asked

How many square metres in an acre?
Exactly 4046.8564224 m² (1 acre = 43 560 ft², and 1 ft² = 0.09290304 m²). The converter returns the exact value, so you avoid the common decimal slip.
What is a hectare in m²?
One hectare is exactly 10 000 m², or 0.01 km². It is the metric land unit used for process yards and tank farms; do not confuse it with a hectare-sized acre (which would be wrong by fourfold).
Is ft² the same as m²?
No. One square foot is about 0.0929 m², so a 100 ft² footprint is roughly 9.29 m². Always convert rather than reading the number as if the unit were the same.
Why do drawings mix m² and ft²?
Metric structure uses m² while imperial components (panels, HVAC, structural steel) quote ft². Convert at the interface to avoid a silent factor error in a footprint or bore area.

This page performs exact unit arithmetic with no physical assumption beyond the stated reference (for example mH₂O assumes water near 4 °C, and pH follows its logarithmic definition). It is a working aid, not a substitute for the measurement method named in your permit.