Feet to US Survey Feet conversion

How to convert feet to us survey feet?

Feet (ft) and US Survey Feet (ft(US)) are both units of measure for length, and while they are very similar, they are not exactly the same. The difference is extremely small but can be significant in certain applications, such as land surveying.

1 international foot (ft) is defined as exactly 0.3048 meters.

1 US survey foot (ft(US)) is defined as exactly 1200/3937 meters, which is approximately 0.3048006096 meters.

Conversion Formula

To convert from international feet (ft) to US survey feet (ft(US)), you can use the following formula:

$\text{US survey feet} = \text{international feet} \times \frac{1 \, \text{ft(US)}}{\text{correction factor}}$

Where the correction factor is approximately 1.000002.

Simplifying:

$\text{US survey feet} = \text{international feet} \times 1.000002$

For 1 international foot:

$1 \, \text{ft} \times 1.000002 \approx 1.000002 \, \text{ft(US)}$

Real World Examples

Here are some illustrations of converting other quantities of feet to US survey feet:

1. 10 international feet to US survey feet: $10 \, \text{ft} \times 1.000002 = 10.00002 \, \text{ft(US)}$

2. 50 international feet to US survey feet: $50 \, \text{ft} \times 1.000002 = 50.0001 \, \text{ft(US)}$

3. 100 international feet to US survey feet: $100 \, \text{ft} \times 1.000002 = 100.0002 \, \text{ft(US)}$

Practical Example

Suppose a land surveyor is working on a plot of land listed as 5000 international feet in length. To convert this distance to US survey feet:

$5000 \, \text{ft} \times 1.000002 = 5000.01 \, \text{ft(US)}$

In this case, a difference of approximately 0.01 feet might only be 0.12 inches, which is minimal, but still important in precise surveying tasks.

Understanding this difference is crucial in contexts where both units might be used interchangeably, such as historical documents, older surveys, or cross-border projects between countries that have adopted different definitions.