Land Area Calculator
Type in the measurements of a plot and see its area in acres, hectares, square feet and square metres.
Need to compare two sizes? Try Which Is Bigger?
A rectangular plot
Example: 120 by 80 feet is 9,600 sq ft, or 891.87 sq m, 0.2204 acres, 0.0892 hectares.
A triangular plot, from its base and height
Example: 100, 60 feet is 3,000 sq ft, or 278.71 sq m, 0.0689 acres, 0.0279 hectares.
A triangular plot, from its three sides
Example: 90, 70, 60 feet is 2,098 sq ft, or 194.88 sq m, 0.0482 acres, 0.0195 hectares.
A four-sided plot
Example: 100, 80, 90, 70, 120 feet is 7,099 sq ft, or 659.53 sq m, 0.163 acres, 0.066 hectares.
Sides in order round the plot. The diagonal joins the corner between sides 1 and 4 to the corner between sides 2 and 3, and should run inside the plot.
A plot with two parallel sides (trapezoid)
Example: 100, 60, 40 feet is 3,200 sq ft, or 297.29 sq m, 0.0735 acres, 0.0297 hectares.
A round plot
Example: 30 feet is 2,827 sq ft, or 262.68 sq m, 0.0649 acres, 0.0263 hectares.
A plot with any number of corners
Example: the corners above make a plot of 7,500 sq ft, or 696.77 sq m, 0.1722 acres, 0.0697 hectares.
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Measure the sides of a plot and this works out its area, then shows it in the units people use for land: square feet, square metres, acres and hectares. It handles rectangles, triangles, circles, four-sided plots and plots with any number of corners.
Land is sold by the acre, listed in square metres and measured in paces, and mixing them up is the classic mistake. One acre is about 4,047 square metres, and one hectare is 10,000 square metres, or about 2.47 acres.
How it's worked out
- Rectangle: length times width. Triangle: half the base times the height, or Heron's formula from the three sides.
- Trapezoid: the average of the two parallel sides times the distance between them. Circle: pi times the radius squared.
- A four-sided plot is split along the diagonal into two triangles that are added up. Corner points use the shoelace formula.
- The area is then converted exactly: 1 acre is 43,560 square feet, 1 hectare is 10,000 square metres.
A plot 120 feet by 80 feet is 9,600 square feet, which is about 892 square metres, 0.22 acres or 0.089 hectares.
Common mistakes
- Mixing units, such as one side in feet and the other in metres. Measure everything in the same unit.
- Measuring along a slope. The area on a map is the flat area, so a sloping plot measured along the ground comes out too big.
- Typing corner points out of order. Go round the edge in one direction, or the shape crosses itself and the area is wrong.
- Using a diagonal that runs outside a four-sided plot. It must cross the inside of the plot.
Questions
How many square feet are in an acre?
43,560. An acre is also about 4,047 square metres, or about 0.405 of a hectare.
How many square metres are in a hectare?
10,000. A hectare is about 2.47 acres.
Is this accurate enough for buying or selling land?
It is exact for the measurements you type in. For a purchase, a boundary question or anything legal, use a licensed surveyor and the official title documents. This tool gives estimates and general information, not professional advice.
What is an are?
An are is 100 square metres, so a hectare is 100 ares. It is used for land in some countries. Enter the area in square metres here and divide by 100.
How do I get corner points from a map or GPS?
Pick one corner as 0, 0 and measure how far each other corner is across (x) and up (y) from it, in the same unit. Then list the corners in order round the edge.
Between clients. Officially research.