Spike's Calculators

Calculate the area of a circle from a diameter measured in metres with results in square metres, hectares and acres.

- the circle's diameter measured in metres
- decimal precision, the number of digits after the decimal point

- area of circle in square metres
- area of circle in hectares
- area of circle in acres

Area of a circle in square metres = (Diam ÷ 2)² * 3.14159

one square metre (m²) = 0.0001 hectares (ha) one square metre (m²) = 0.000247105381467165 acres (ac)

Circle with a diameter of 30 metres

30 ÷ 2 = 15 * 15 * 3.14159 = 706.858 square metres

The circle has an area of 706.858 square metres

- Area of a Circle from Diameter in Metres
- Area of a Circle from Foot and Inch Diameter
- Basal Area from Diameter in Centimetres
- Basal Area from Diameter in Inches
- Basal Area from Girth Measured @ Breast Height in Centimetres
- Basal Area from Girth Measured @ Breast Height in Inches
- Circumference (Girth) of a Log from Diameter, Foot and Inch
- Convert Diameter in Centimetres to Girth in Inches
- Circumference (Girth) of a Log from Diameter, Inch and Fraction
- Diameter of Tree from Circumference Measurement
- Diameter/Centimetres to Inches/Quarter Girth
- Fixed Area Plot, Acres
- Fixed Area Plots, Hectares
- Number of Trees and Tree Spacing Calculated from Basal Area
- Square Feet (Quarter Girth) to Square Centimetres
- Square Feet (Quarter Girth) to Square Metres
- Trees per Hectare to Trees per Acre
- Trees per Acre to Trees per Hectare