Play with php built-in array_sum(), array_map(), array_filter() to calculate yearly savings from arbitrary taxes and income.

declarative-expenses.php

<?php
  
$annualExpenses = [
    "vacations" => 1000,
    "carRepairs" => 1000,    
];

$monthlyExpenses = [
    "rent" => 1500,
    "utilities" => 200,
    "healthInsurance" => 200
];

$weeklyExpenses = [
    "gas" => 25,
    "food" => 90,
    "entertainment" => 47
];

$grossSalary = 48150;
$socialSecurity = $grossSalary * .062;

$incomeSegments = [[9700, .88], [29775, .78], [8675, .76]];

$netIncome = array_sum(array_map(function($array){
  return $array[0] * $array[1];
}, $incomeSegments));

$netIncome -= $socialSecurity;
$annualIncome = $netIncome;
echo "Annual income before deducting annual expenses:\n$annualIncome\n";

$annualIncome -= array_sum($annualExpenses);
echo "Annual income after deducting annual expenses:\n$annualIncome\n";

$monthlyIncome = $annualIncome/12;
echo "\nMonthly income before deducting monthly expenses:\n$monthlyIncome\n";

$monthlyIncome -= array_sum($monthlyExpenses);
echo "\nMonthly income after calculation:\n$monthlyIncome \n";

$weeklyIncome = $monthlyIncome/4.33;
echo "\nWeekly income before calculation:\n$weeklyIncome\n";

$weeklyIncome -= array_sum($weeklyExpenses);
echo "\nWeekly income after calculation:\n$weeklyIncome\n";

$leftoverMoney = $weeklyIncome * 52;
echo "\nRemaining income: $leftoverMoney";