Housing Bubble Calculator
Is your local housing market overvalued? Enter local market data to get a composite bubble risk score based on 5 key indicators — price-to-income, price-to-rent, affordability, inventory, and real price appreciation.
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Bubble Risk Score
Elevated Risk
Composite score: 2.6 / 4.0 · 5 indicators analyzed
Price-to-Income
6.0x (Elevated)
Price-to-Rent
17.0x (Moderate)
Affordability (% Income)
37.4% (Moderate)
Inventory
2.5 mo (Elevated)
Real Price Appreciation
12.0% (Elevated)
Monthly Pmt (Median Home)
$2,335/mo
Advanced
5-Indicator Deep Dive & Historical Comparison
Each indicator scored and explained, comparison to 2006 peak bubble levels
Each indicator tells a different part of the overvaluation story. Bubbles rarely show in just one metric — when 3+ indicators flash red, the risk is real.
Price-to-Income Ratio
ElevatedYour Market
6.0x
Historical Avg
3.5x
2006 Peak
6.2x
Your market: 6.0x income. US historical median: 3.5x. 2006 peak: 6.2x nationally. Above 5x = caution; above 6.5x = significant overvaluation.
Price-to-Rent Ratio
ModerateYour Market
17.0x
Historical Avg
16.0x
2006 Peak
24.0x
Your market: 17.0x annual rent. Historical: 16x. 2006 peak: 24x. Above 20x buying loses economic advantage over renting.
Mortgage Payment as % of Income
ModerateYour Market
37.4%
Historical Avg
30.0%
2006 Peak
48.0%
Monthly payment ($2,335) on median home at 20% down = 37.4% of median income. Historical: ~30%. 2006 peak: ~48%.
Months of Housing Supply
ElevatedYour Market
2.5 mo
Historical Avg
5.0 mo
2006 Peak
0.8 mo
Balanced market: 4-6 months. Below 3 months = seller's market, price pressure. You entered 2.5 months. At the 2006 peak, many markets had 0.5-1.0 months of supply.
Real Price Change (1 Yr)
ElevatedYour Market
12.0%
Historical Avg
3.0%
2006 Peak
15.0%
Sustainable long-run real (inflation-adjusted) appreciation: ~2-3%. You entered 12.0%. Above 10% real gains = unsustainable; above 15% = bubble territory.
Pro
Scenario Modeling, Timing & Protection Strategy
Equity impact if prices correct, historical timelines, when to wait vs buy
If prices correct, what happens to your equity and what does the market look like for buyers?
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10% Price Correction
$405,000
Equity after: $55,000
New PTI: 5.4x
New PTR: 15.3x
Affordability: 33.6%
Monthly pmt: $2,101
20% Price Correction
$360,000
Equity after: $10,000
New PTI: 4.8x
New PTR: 13.6x
Affordability: 29.9%
Monthly pmt: $1,868
30% Price Correction
$315,000
Equity after: -$35,000
Underwater by $35,000
New PTI: 4.2x
New PTR: 11.9x
Affordability: 26.2%
Monthly pmt: $1,634
With 22% equity, a 20% correction would reduce equity to $10,000 — you'd remain above water but would see significant paper losses.
How to Use This Housing Bubble Calculator
Enter local market data for the metro area you're analyzing:
- Median Home Price: Current median sale price in your target market. Find this on Zillow, Redfin, or your local MLS.
- Median Household Income: From Census.gov ACS data or a quick search for "[city] median household income." Use the most recent year.
- Median Monthly Rent: For a comparable property — 2-3 bedroom in the same area. Check Zillow Rent Index or RealPage.
- Months of Supply: Active listings divided by monthly closings. Available from your local Realtor association or Altos Research. Below 3 months = seller's market.
- Real Price Change: Take the trailing 12-month price appreciation and subtract the current inflation rate (~3%) to get real appreciation.
The 5 Bubble Indicators Explained
Price-to-Income = Median Home Price ÷ Median Household Income
Price-to-Rent = Median Home Price ÷ (Monthly Rent × 12)
Affordability % = Monthly Mortgage Payment ÷ Monthly Gross Income
(Assumes 30-year fixed, 20% down, current rate)
Bubble Risk: Low (<2.0) · Moderate (2.0-2.5) · Elevated (2.5-3.2) · High (>3.2)
Price-to-Rent = Median Home Price ÷ (Monthly Rent × 12)
Affordability % = Monthly Mortgage Payment ÷ Monthly Gross Income
(Assumes 30-year fixed, 20% down, current rate)
Bubble Risk: Low (<2.0) · Moderate (2.0-2.5) · Elevated (2.5-3.2) · High (>3.2)
No single indicator defines a bubble. The 2006 bubble showed all 5 indicators in the danger zone simultaneously. Today's elevated-rate environment is unusual — affordability is stressed by high rates rather than lax lending standards, which changes the correction dynamics.
Important Limitation
Markets can stay "overvalued" by these metrics for years if there is a genuine supply constraint (San Francisco's geographic limits, Manhattan's island constraints) or strong income growth. Use these indicators as a framework for risk assessment, not as a precise prediction tool.
Historical Context: The 2006 Bubble vs. Today
Key Differences Between 2006 and Current Market
| Lending Standards | 2006: Near-zero documentation, subprime ARMs, 0% down | Today: Strict income verification, mostly fixed-rate mortgages, 5%+ down |
| Price Driver | 2006: Speculative demand + lax credit | Today: Genuine supply shortage + pandemic migration + rate lock-in effect |
| Homeowner Equity | 2006: Average 8% equity — extreme leverage | Today: Average 40%+ equity — massive cushion against forced selling |
| Investor Share | 2006: 20-25% investor purchases | Today: 15-18% investor purchases — lower but still elevated |
| Correction Risk | 2006: Systemic — banking system exposure | Today: Localized — rate-sensitive markets, overbuilt metros at higher risk |
Frequently Asked Questions
Housing bubbles are identified through multiple indicators: (1) Price-to-income ratio above 5x (historical average: 3.5x), (2) Price-to-rent ratio above 20x (historical: 16x), (3) Mortgage payment exceeding 35-40% of median income, (4) Inventory below 2-3 months of supply, (5) Real price appreciation above 10% annually. When 3+ indicators are in the danger zone simultaneously, the risk of a correction is meaningful.
The price-to-income ratio is median home price divided by median household income. Historically, the US average has been 3-4x income. Below 4x is generally affordable. At 5-6x, buyers are stretched. Above 6.5x is classic bubble territory — nationally, the 2006 peak reached approximately 6.2x. Individual markets (San Francisco, LA) can reach 9-12x income due to supply constraints.
The price-to-rent ratio compares home prices to annual rents (Home Price ÷ Annual Rent). The US historical average is approximately 15-16x. Below 15x: buying is economically favorable. At 15-20x: roughly break-even. Above 20x: renting becomes more efficient. At the 2006 peak, many markets reached 25-30x, meaning you could rent a home for 4% of its value annually.
The 2006-2012 crash saw national prices fall approximately 33% peak-to-trough over 6 years. Some markets fell 50-60% (Phoenix, Las Vegas, Miami). Recovery to pre-crash levels took 6-8 years nationally, though some markets (Seattle, Denver) recovered faster and others (Detroit, Cleveland) still haven't returned to 2006 nominal prices. Long hold periods (7+ years) are recommended in overvalued markets.
In most historical corrections, people who waited paid years of rent that often exceeded the purchase price savings — unless they timed the bottom perfectly. The math generally favors buying if you plan to hold 7+ years, can comfortably afford the payment today, and have 20%+ down. Waiting makes more sense if the expected correction exceeds 20%, you have a short hold horizon, or your equity buffer is thin.