How much does a 1% rate increase affect buying power?

A 1% rate increase reduces buying power by approximately 10-11% for a given monthly payment. On a $500,000 home budget that's roughly $50,000-$55,000 less home. The exact impact depends on your starting rate — the relationship is non-linear with larger swings at higher rate levels.

Should I wait for rates to drop before buying?

Waiting for rate drops risks: rates may rise instead, and lower rates bring more buyers increasing home prices so rate gains get offset. The general wisdom is marry the house date the rate — buy now and refinance when rates improve. Use the Waiting Cost calculator to see your specific scenario.

What is a mortgage rate buydown?

A buydown means paying upfront points to permanently lower your rate. One point costs 1% of the loan and reduces rate ~0.25%. On a $400,000 loan one point costs $4,000 and saves $60-75/month. Break-even is typically 4-6 years. Worth it if you stay past break-even.

When does an ARM make more sense than a fixed rate?

An ARM makes sense when you plan to sell before the fixed period ends (5, 7, or 10 years), expect income to rise making potential payment shock manageable, and the ARM rate is meaningfully lower (at least 0.5-1% below fixed). The key risk is underestimating how long you'll stay.

Is it better to save more down payment or buy now at a higher rate?

This depends on savings speed, rate trajectory, and home price appreciation. If you save $500/month for 12 months but rates rise 0.5%, the rate increase likely costs more buying power than the extra down payment adds. Use the Waiting Cost tab to calculate your specific scenario.

Interest Rate Buying Power Calculator

See exactly how rising or falling interest rates change what you can afford. Compare buying power across rates from 4% to 9%, understand the real cost of waiting, and model buydown and ARM strategies to maximize your purchasing power.

Rate Impact on Buying Power

Monthly Housing Budget

Down Payment Available

Current Interest Rate

Loan Term

yrs

Max Home Price (Current Rate)

$445,447

$385,447 loan at 6.8%

Max Price at −0.5% Rate

$466,031

$20,584 more buying power

Max Price at +0.5% Rate

$426,474

$18,973 less buying power

Max Price at −1% Rate

$488,396

$42,949 more buying power

Max Price at +1% Rate

$408,961

$36,486 less buying power

Buying Power Change per 0.25% Rate Move

-1.00% rate → 5.8%

+$42,949

$488,396 total

-0.50% rate → 6.3%

+$20,584

$466,031 total

-0.25% rate → 6.5%

+$10,080

$455,527 total

+0.25% rate → 7.0%

-$9,678

$435,769 total

+0.50% rate → 7.3%

-$18,973

$426,474 total

+1.00% rate → 7.8%

-$36,486

$408,961 total

Advanced

Rate Impact Table, Historical Context & Waiting Cost

Full rate matrix from 4% to 9%, how today's rate compares to history, and the cost of waiting to save more

Max home price, monthly payment, and total interest across rates — with $2,500/mo budget and $60,000 down:

Rate	Max Home Price	Monthly P&I	Total Interest
4.0%	$583,653	$2,500	$376,347
4.5%	$553,403	$2,500	$406,597
5.0%	$525,704	$2,500	$434,296
5.5%	$500,304	$2,500	$459,696
6.0%	$476,979	$2,500	$483,021
6.5% ← today	$455,527	$2,500	$504,473
7.0% ← today	$435,769	$2,500	$524,231
7.5%	$417,544	$2,500	$542,456
8.0%	$400,709	$2,500	$559,291
8.5%	$385,134	$2,500	$574,866
9.0%	$370,705	$2,500	$589,295

Pro

Buydown Strategy, ARM Opportunity & Market Timing

Cost of buying points vs buying power gained, 5/1 ARM advantage, and rate scenario strategies

Loan Amount

Points to Buy

pts

Years You Plan to Stay

yrs

Points Cost

$3,500

1.0% of $350,000 loan

Rate After Buydown

6.5%

Down from 6.8% · saves 0.3%

Monthly Payment Savings

$58

Per month at lower rate

Break-Even Month

61 months

5.1 years to recover points cost

Total Savings over Hold Period

$1,360

Over 7-year hold period

Added Buying Power

$10,080

Higher home budget with same monthly payment

Buydown likely worth it: You break even in 5.1 years and plan to stay 7 years. The buydown saves $1,360 net over your hold period.

How to Use This Interest Rate Buying Power Calculator

This calculator answers one specific question: how does the mortgage interest rate change what home you can afford? It is distinct from an affordability calculator — this tool takes your monthly budget as fixed and shows how your buying power shifts as rates move up or down in 0.25% increments.

Quick Section: Rate Sensitivity

Enter your maximum monthly housing budget (principal and interest only), available down payment, current rate, and loan term. The calculator immediately shows your maximum home price at the current rate, and how that buying power changes at rates up to 1% higher or lower. The buying power change per 0.25% rate move is displayed prominently — this is the core number to understand when deciding whether to wait for rates to drop.

Advanced: Rate Table, Historical Context, and Waiting Cost

The Rate Impact Table shows a full matrix from 4% to 9% rates — maximum home price, monthly payment, and total interest at each rate, with your current rate highlighted. The Historical Context tab compares today's buying power to historical rate environments including the 1-year ago rate, 5- and 10-year averages, and the all-time average of 7.74%. The Waiting Cost tab calculates whether saving more down payment for a set number of months offsets the risk of a 0.5% rate increase during that period.

Pro: Buydown, ARM, and Market Timing Strategies

The Buydown tab calculates the cost of buying mortgage points to lower your rate, the monthly savings, and break-even time — with an assessment of whether it is worth it given your hold period. The ARM tab shows how much extra buying power a 5/1 ARM provides during the fixed period, and what payment shock looks like at reset. The Market Timing tab provides actionable strategies for three rate scenarios: stable, dropping, and rising.

Key Formulas

Max Loan = Monthly Budget × [(1+r)^n − 1] / [r × (1+r)^n]
where r = monthly rate (annual rate ÷ 12), n = months

Max Home Price = Max Loan + Down Payment

Buying Power Change = Max Home Price(rate A) − Max Home Price(rate B)

Buydown Break-Even = Points Cost ÷ Monthly Payment Savings

Waiting Cost = Buying Power(current rate) − Buying Power(rate+0.5%, more down)

A key insight: because of how loan amortization works, buying power is not linear with rate changes. A 1% rate decrease adds significantly more buying power at higher rate levels than at lower rate levels. The relationship is convex — larger rates produce disproportionately large buying power swings.

Example: Sarah's Rate Decision in Denver

Scenario: $3,000/month budget, $80,000 down, comparing rates

Monthly Budget (P&I)	$3,000
Down Payment	$80,000
At 5.00% Rate	$638,000 max home price
At 6.75% Rate (current)	$530,000 max home price
At 7.50% Rate (+0.75%)	$497,000 max home price
Buying Power: 5% vs 6.75%	$108,000 difference
Buying Power: 6.75% vs 7.5%	$33,000 difference
Per 0.25% Rate Move	~$14,000 buying power swing

Sarah is deciding whether to wait for rates to drop. Each 0.25% rate move changes her buying power by about $14,000. If rates drop 1% to 5.75%, she gains $52,000 in buying power — but Denver home prices may rise in that period, consuming much of that gain.

Frequently Asked Questions

A 1% rate increase reduces buying power by approximately 10-11% for a given monthly payment. On a $500,000 home budget, that's roughly $50,000-$55,000 less home. Conversely, a 1% rate decrease increases your buying power by a similar amount. The exact impact depends on your starting rate — the relationship is non-linear, with larger swings at higher rate levels.

Waiting for rate drops has two risks: (1) rates may not drop — they could rise, reducing your buying power further; (2) lower rates bring more buyers into the market, increasing competition and potentially driving up home prices, so your rate-drop gain may be partially offset by higher prices. The general wisdom is "marry the house, date the rate" — buy the home you want now and refinance when rates improve. However, if rates are clearly at a peak and expected to fall, short-term waiting can make sense.

A mortgage rate buydown means paying upfront "points" to permanently lower your interest rate. One point costs 1% of the loan amount and typically reduces the rate by about 0.25%. On a $400,000 loan, one point costs $4,000 and might save $60-75/month. The break-even is typically 4-6 years. Buydowns make sense if you plan to stay in the home past the break-even point and have the cash available after closing.

An ARM (adjustable-rate mortgage) makes sense when: (1) you plan to sell or move before the fixed period ends — typically 5, 7, or 10 years; (2) you expect your income to rise significantly, so the potential payment increase at reset is manageable; (3) the ARM rate is meaningfully lower than the fixed rate (at least 0.5-1% lower). The key risk is underestimating how long you'll stay — ARM rates can reset significantly higher, causing payment shock.

This depends on three factors: how fast you can save additional down payment, whether rates are likely to rise during the waiting period, and how fast home prices are appreciating. If you can save $500/month and it takes 12 months to save $6,000 more down, but rates rise 0.5% in that period, the rate increase likely costs more buying power than the extra down payment adds. Use the Waiting Cost tab to calculate your specific scenario.