body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background-color: #f9f9f9;
}
.calculator-container {
background: #ffffff;
padding: 30px;
border-radius: 12px;
box-shadow: 0 4px 15px rgba(0,0,0,0.1);
margin-bottom: 40px;
border: 1px solid #e1e1e1;
}
.calculator-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.input-group {
margin-bottom: 20px;
}
label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #555;
}
.input-wrapper {
position: relative;
}
.currency-symbol {
position: absolute;
left: 12px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
input[type="number"] {
width: 100%;
padding: 12px 12px 12px 30px;
border: 2px solid #ddd;
border-radius: 8px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.3s;
}
input[type="number"]:focus {
border-color: #3498db;
outline: none;
}
.btn-calc {
width: 100%;
background-color: #2c3e50;
color: white;
padding: 15px;
border: none;
border-radius: 8px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s;
margin-top: 10px;
}
.btn-calc:hover {
background-color: #34495e;
}
#result-area {
margin-top: 30px;
padding: 20px;
background-color: #f0f7fb;
border-radius: 8px;
display: none;
border-left: 5px solid #3498db;
}
.result-row {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 10px;
}
.result-label {
font-weight: 600;
color: #555;
}
.result-value {
font-size: 24px;
font-weight: 800;
color: #2c3e50;
}
.interpretation {
margin-top: 15px;
padding-top: 15px;
border-top: 1px solid #dcebf5;
font-size: 15px;
color: #444;
}
.badge {
display: inline-block;
padding: 4px 10px;
border-radius: 4px;
color: white;
font-weight: bold;
font-size: 14px;
}
.badge-affordable { background-color: #27ae60; }
.badge-moderate { background-color: #f39c12; }
.badge-serious { background-color: #e67e22; }
.badge-severe { background-color: #c0392b; }
.content-section {
background: white;
padding: 30px;
border-radius: 12px;
border: 1px solid #e1e1e1;
}
h2 { color: #2c3e50; margin-top: 30px; }
h3 { color: #34495e; margin-top: 25px; }
p { margin-bottom: 15px; }
ul { margin-bottom: 20px; padding-left: 20px; }
li { margin-bottom: 8px; }
.formula-box {
background-color: #eee;
padding: 15px;
border-radius: 6px;
font-family: monospace;
text-align: center;
font-size: 1.2em;
margin: 20px 0;
border: 1px solid #ccc;
}
function calculatePIR() {
// Get input values using direct ID selection as required
var priceInput = document.getElementById("medianHomePrice");
var incomeInput = document.getElementById("householdIncome");
var resultArea = document.getElementById("result-area");
var pirScoreDisplay = document.getElementById("pirScore");
var statusBadge = document.getElementById("statusBadge");
var interpretationText = document.getElementById("interpretationText");
// Parse values
var price = parseFloat(priceInput.value);
var income = parseFloat(incomeInput.value);
// Validation logic
if (isNaN(price) || isNaN(income) || price <= 0 || income <= 0) {
alert("Please enter valid positive numbers for both Property Value and Income.");
resultArea.style.display = "none";
return;
}
// Calculation: Price divided by Income
// This represents the number of years of gross income required to purchase the property
var pir = price / income;
// Display Logic
resultArea.style.display = "block";
pirScoreDisplay.innerText = pir.toFixed(2);
// Determination of Affordability Categories
// Based on standard Demographia International Housing Affordability Survey categories
var status = "";
var badgeClass = "";
var explanation = "";
if (pir 3.0 && pir 4.0 && pir <= 5.0) {
status = "Seriously Unaffordable";
badgeClass = "badge-serious";
explanation = "A PIR of " + pir.toFixed(2) + " is classified as seriously unaffordable. The property price represents " + pir.toFixed(1) + " years of total household income, significantly stretching financial limits.";
} else {
status = "Severely Unaffordable";
badgeClass = "badge-severe";
explanation = "A PIR of " + pir.toFixed(2) + " is severely unaffordable. In this range, housing costs are significantly disconnected from earnings, often indicating a housing bubble or a high-demand luxury market.";
}
// Apply classes and text
statusBadge.className = "badge " + badgeClass;
statusBadge.innerText = status;
interpretationText.innerText = explanation;
}
What is the PIR (Price to Income Ratio)?
The Price to Income Ratio (PIR) is a fundamental economic indicator used to assess housing affordability in a specific area. Unlike mortgage calculators that focus on monthly payments and interest rates, the PIR looks at the structural relationship between real estate prices and household earnings.
Specifically, the PIR answers the question: "How many years of gross annual income would it take to buy a median-priced home outright?" It is widely used by economists, urban planners, and prospective homebuyers to determine if a housing market is overvalued or if a specific property is within a reasonable financial reach.
How to Calculate PIR Rate
The formula for calculating the Price to Income Ratio is straightforward but powerful. It removes the variables of down payments and mortgage terms to provide a raw affordability score.
PIR = Median Home Price / Gross Annual Household Income
Example Calculation:
If the median home price in your city is $500,000 and your household's gross annual income is $100,000, the calculation is:
- $500,000 / $100,000 = 5.0
This results in a PIR of 5.0, meaning it costs five years of total income to purchase a property.
Interpreting Your PIR Score
The Demographia International Housing Affordability Survey provides a standard scale for interpreting PIR scores. Understanding where your ratio falls can help you make safer financial decisions regarding real estate investment.
- 3.0 or Less (Affordable): This is the historic standard for affordability. Markets or purchases in this range allow households to service debt comfortably while saving for other goals.
- 3.1 to 4.0 (Moderately Unaffordable): This range is common in growing metropolitan areas. It requires careful budgeting but is often manageable.
- 4.1 to 5.0 (Seriously Unaffordable): Buying in this range often leads to "house poor" situations where a disproportionate amount of income goes toward housing costs.
- 5.1 and Above (Severely Unaffordable): Scores in this range are typical of housing bubbles or extremely high-demand cities (e.g., Hong Kong, Sydney, San Francisco). Purchasing here carries significant financial risk.
Why is PIR Important?
While lenders use Debt-to-Income (DTI) ratios to approve loans, the PIR helps you understand the asset value relative to your earning power. A low interest rate might make a monthly payment look affordable even if the PIR is high, but a high PIR indicates that the principal debt load is massive relative to your income.
Using a PIR calculator helps you avoid over-leveraging and ensures you are buying a home that aligns with long-term financial stability, regardless of temporary fluctuations in interest rates.