Area Calculator
Choose a shape and enter its dimensions in any unit: a 40 m × 25 m rectangular plot has an area of 1000 m², which is 0.1 hectare or about 0.247 acre.
40 m²
- Area
- 40 m²
- Perimeter
- 26 m
- Diagonal
- 9.43398 m
In other units: 400000 cm² · 40000000 mm² · 0.00004 km² · 0.004 ha · 430.556 ft² · 62000.1 in² · 47.8396 yd² · 0.00988422 ac · 0.0000154441 mi²
Step-by-step solution
- A = l × w
- A = 8 × 5 = 40 m²
Area Formula
A = l × w, ½bh, πr² …
Each shape has its own formula; pick the shape to see it
Worked Example
A 40 m × 25 m plot:
- A = l × w
- A = 40 × 25 = 1000 m²
Perimeter: 130 m · Diagonal: 47.1699 m
Same area in other units: 10000000 cm² · 1000000000 mm² · 0.001 km² · 0.1 ha · 10763.9 ft²
All Area Formulas
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Area of a Square Calculator
A = a² = d² ÷ 2
a side length, d diagonal
Example: A square with 5 cm sides: Area A = 25 cm².
-
Area of a Rectangle Calculator
A = l × w
l length, w width
Example: An 8 m × 5 m room: Area A = 40 m².
-
Area of a Triangle Calculator
A = ½ b h = √[s(s−a)(s−b)(s−c)]
b base, h height, a b c sides, s = (a+b+c)/2
Example: A triangle with sides 5, 6 and 7 cm: Area A = 14.6969 cm².
-
Area of a Circle Calculator
A = π r² = π d² ÷ 4
r radius, d diameter, π ≈ 3.14159
Example: A circle with a 5 cm radius: Area A = 78.5398 cm².
-
Area of a Trapezoid Calculator
A = ½ (a + b) h
a, b parallel sides, h perpendicular height
Example: A trapezoid with parallel sides 8 cm and 5 cm and height 4 cm: Area A = 26 cm².
-
Area of a Parallelogram Calculator
A = b × h
b base, h perpendicular height
Example: A parallelogram with a 9 cm base and 4 cm height: Area A = 36 cm².
-
Area of a Rhombus Calculator
A = d₁ × d₂ ÷ 2
d₁, d₂ diagonals
Example: A rhombus with diagonals 10 cm and 6 cm: Area A = 30 cm².
-
Area of an Ellipse Calculator
A = π a b
a semi-major axis, b semi-minor axis
Example: An ellipse with semi-axes 6 cm and 4 cm: Area A = 75.3982 cm².
-
Area of a Sector Calculator
A = (θ ÷ 360°) π r² = ½ r² θ
r radius, θ central angle (degrees, or radians in ½r²θ)
Example: A 60° sector of a 6 cm radius circle: Area A = 18.8496 cm².
-
Area of a Semicircle Calculator
A = π r² ÷ 2 = π d² ÷ 8
r radius, d diameter
Example: A semicircle with a 5 cm radius: Area A = 39.2699 cm².
-
Area of a Regular Polygon Calculator
A = n s² ÷ (4 tan(π ÷ n))
n number of sides, s side length
Example: A regular hexagon with 4 cm sides: Area A = 41.5692 cm².
-
Area of a Ring (Annulus) Calculator
A = π (R² − r²)
R outer radius, r inner radius
Example: A ring with outer radius 10 cm and inner radius 6 cm: Area A = 201.062 cm².
Frequently asked questions
How do I calculate the area of an irregular plot of land?
Split it into rectangles and triangles, work out each area with its own formula, and add them up. For a four-sided plot, draw one diagonal and use the three-sides (Heron) triangle formula for each half.
How do I calculate area in square feet from feet and inches?
Convert inches to feet first (divide by 12), then multiply. A room 12 ft 6 in × 10 ft is 12.5 × 10 = 125 ft². Or choose inches as the length unit and show the result in ft².
What is the difference between area and perimeter?
Area is the space inside a shape, in square units (m², ft²). Perimeter is the distance around it, in length units (m, ft).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Area Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/area-calculator/
IEEE
Scientific Converters, "Area Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/area-calculator/