Land calculation

The problem

One acre of land is equivalent to 43,560 square feet. Write a program that calculates the number of acres in a tract of land with 389,767 square feet.

Breaking it down

Create constant

private static final int FEET_PER_ACRE = 43560;

Write method to calculate acres

 * Should calculate the number of acres.
 * @param tract
 * @return double
static double calculateAcres(double tract) {
    return tract / FEET_PER_ACRE;

Create variables, scanner for keyboard input

double tract;
double acres;

Scanner keyboard = new Scanner(;

System.out.println("This program will calculate number of acres.");

Get user input, calculate acres

System.out.print("Enter tract in feet: ");

tract = keyboard.nextDouble();

acres = calculateAcres(tract);

Display results

System.out.println("A tract of land with " + tract + " square feet has " + acres + " acres.");


This program will calculate number of acres.
Enter tract in feed: 30
A tract of land with 30.0 square feet has 6.887052341597796E-4 acres.

Unit tests

public void calculateAcres () {
    assertEquals(68.87105142332415, LandCalculation.calculateAcres(3000023), 0);

Level Up

  • Allow user to tract in another user of measurement. What will you need to allow a user to do?
  • Validate user input