<html>
<head>
<script src="tax.js"></script>
-</script>
+<script src="tax_ui.js"></script>
+<style>
+ td { padding: .5em; vertical-align: top}
+ textarea { height: 12em; }
+ input { width: 7em }
+</style>
</head>
-<body>
+<body onload="calculate()">
+<h1>Inverse income tax tool</h1>
+<p>What gross salary is needed to provide a specified after-tax salary?</p>
+
+<form>
+<table>
+<tr>
+<td>
+Federal deductible<br/><input id="deductible_1" value="24000"/>
+</td>
+<td>
+State deductible<br/><input id="deductible_2" value="8258"/>
+</td>
+</tr>
+<tr>
+<td>
+Federal tax table<br/>
+<textarea id="tax_table_1"> 0 10
+ 18651 15
+ 75901 25
+153101 28
+233351 33
+416701 35
+470001 39.6</textarea>
+</td>
+<td>
+State tax table<br/>
+<textarea id="tax_table_2"> 0 1
+ 16030 2
+ 38002 4
+ 59978 6
+ 83258 8
+ 105224 9.3
+ 537500 10.3
+ 644998 11.3
+1000000 12.3
+1074996 13.3</textarea>
+<br/>(Initial table is California's)
+</td>
+</tr>
+<tr>
+<td colspan="2">
+Desired after-tax salary</br>
+<input id="after_tax" value="100000" onchange="calculate()" oninput="calculate()">
+</td></tr>
+</table>
+</form>
+
+<p><strong><span id="before_tax"></span> before tax</strong>
+ - <span id="tax_1"></span> federal tax
+ - <span id="tax_2"></span> state tax
+ = <span id="after_tax_verification"></span> after tax.</p>
+
+<p>Privacy policy: All calculations are client-side; no figures are sent to any server.</p>
</body>
</html>
--- /dev/null
+function load_tax_table(table_id, deductible_id) {
+ return apply_deductible(parse_tax_table(document.getElementById(table_id).value),
+ parseFloat(document.getElementById(deductible_id).value));
+}
+
+function format_number(n) {
+ return n.toLocaleString('en', {useGrouping:true, style: 'currency', currency: 'USD'});
+}
+
+function calculate() {
+ const table1 = load_tax_table('tax_table_1', 'deductible_1');
+ const table2 = load_tax_table('tax_table_2', 'deductible_2');
+ const after_tax = parseFloat(document.getElementById('after_tax').value);
+
+ const before_tax = invert(merge_tax_tables(table1, table2))(after_tax);
+
+ const tax1 = tax(table1, before_tax);
+ const tax2 = tax(table2, before_tax);
+
+ document.getElementById('before_tax').textContent = format_number(before_tax);
+ document.getElementById('tax_1').textContent = format_number(tax1);
+ document.getElementById('tax_2').textContent = format_number(tax2);
+ document.getElementById('after_tax_verification').textContent = format_number(before_tax - (tax1 + tax2));
+}
projects / inverse-tax / commitdiff