Spike's Calculators

# Octagon

Calculate the area and perimeter of a octagon. This calculator uses feet and or inches for measurements.

Octagon = a shape with eight equal length sides.

### Octagon Area and Perimeter

Side Length ft in n
d
Decimal Precision

#### Results:

Short Diagonal Length (sd) ft
Side to Side Length (ss) ft
Long Diagonal Length (ld) ft
###### Area of the Octagon
Decimal Square Feet ft²
Square Feet ft² in²
Decimal Square Inches in²
Square Inches in²
Square Metres
###### Perimeter of the Octagon:
Decimal Feet ft
Feet ft in
Decimal Inches in
Inches in
Metres m

#### Calculation

1. side length in feet and or inches
2. decimal precision, the number of digits after the decimal point

#### Results

1. length of the long diagonal (ld) in decimal feet
2. side to side length (ss) in decimal feet
3. length of the short diagonal (sd) in decimal feet
4. the area of the octagon in decimal square feet
5. area in square feet and inches
6. the area in decimal square inches
7. the area in square inches
8. the area in square metres
9. the perimeter of the octagon in decimal feet
10. the perimeter in lineal feet and inches
11. the perimeter in decimal inches
12. the perimeter in inches
13. the perimeter in metres

##### Formula
```A = 4.8284271a²
P = a8
where A is the area of the octagon
a the length of a side
P the perimeter of the octagon
```

##### Conversions
```one square foot ( ft²) = 144 square inches (in²)
one square inch (in²) = 0.00694444444444443 square feet (ft²)
one square foot ( ft²) = 0.09290304 square metres (m²)
square inch (in²) = 0.00064516 square metres (m²)
```