# Definition:Imperial/Length

## Definition

The imperial units of length are as follows:

### Mil

 $\displaystyle$  $\displaystyle 1$ mil $\displaystyle$ $=$ $\displaystyle \dfrac 1 {1000}$ inch $\displaystyle$ $=$ $\displaystyle 25 \cdotp 4$ microns $\displaystyle$ $=$ $\displaystyle 0 \cdotp 0254$ millimetres $\displaystyle$ $=$ $\displaystyle 2 \cdotp 54 \times 10^{-5}$ metres

### Inch

 $\displaystyle$  $\displaystyle 1$ inch $\displaystyle$ $=$ $\displaystyle 2 \cdotp 54$ centimetres $\displaystyle$ $=$ $\displaystyle 0 \cdotp 0254$ metres

This definition is exact, and is how the imperial unit of length is defined.

### Foot

The foot is the FPS base unit of length.

 $\displaystyle$  $\displaystyle 1$ foot $\displaystyle$ $=$ $\displaystyle 12$ inches $\displaystyle$ $=$ $\displaystyle 30.48$ centimetres $\displaystyle$ $=$ $\displaystyle 0 \cdotp 3048$ metres

### Yard

 $\displaystyle$  $\displaystyle 1$ yard $\displaystyle$ $=$ $\displaystyle 3$ feet $\displaystyle$ $=$ $\displaystyle 36$ inches $\displaystyle$ $=$ $\displaystyle 91 \cdot 44$ centimetres $\displaystyle$ $=$ $\displaystyle 0 \cdotp 9144$ metres

### Rod, Pole or Perch

 $\displaystyle$  $\displaystyle 1$ rod, pole or perch $\displaystyle$ $=$ $\displaystyle 5 \tfrac 1 2$ yards $\displaystyle$ $=$ $\displaystyle 16 \tfrac 1 2$ feet $\displaystyle$ $=$ $\displaystyle 502 \cdot 92$ centimetres $\displaystyle$ $=$ $\displaystyle 5 \cdotp 0292$ metres

### Chain

 $\displaystyle$  $\displaystyle 1$ chain $\displaystyle$ $=$ $\displaystyle 4$ rods, poles or perches $\displaystyle$ $=$ $\displaystyle 22$ yards $\displaystyle$ $=$ $\displaystyle 66$ feet $\displaystyle$ $=$ $\displaystyle 20 \cdotp 1168$ metres

### Furlong

 $\displaystyle$  $\displaystyle 1$ furlong $\displaystyle$ $=$ $\displaystyle 10$ chains $\displaystyle$ $=$ $\displaystyle 40$ rods, poles or perches $\displaystyle$ $=$ $\displaystyle 220$ yards $\displaystyle$ $=$ $\displaystyle 660$ feet $\displaystyle$ $=$ $\displaystyle 201 \cdotp 168$ metres

### International Mile

 $\displaystyle$  $\displaystyle 1$ (international) mile $\displaystyle$ $=$ $\displaystyle 8$ furlongs $\displaystyle$ $=$ $\displaystyle 80$ chains $\displaystyle$ $=$ $\displaystyle 320$ rods, poles or perches $\displaystyle$ $=$ $\displaystyle 1760$ yards $\displaystyle$ $=$ $\displaystyle 1609 \cdotp 344$ metres (exactly)

### League

 $\displaystyle$  $\displaystyle 1$ league $\displaystyle$  $\displaystyle 3$ (international) miles $\displaystyle$ $=$ $\displaystyle 5280$ yards $\displaystyle$ $\approx$ $\displaystyle 2$ leuca $\displaystyle$ $\approx$ $\displaystyle 3000$ paces $\displaystyle$ $=$ $\displaystyle 4828 \cdotp 032$ metres (exactly)