Is 5% down a mistake at a high interest rate?

Not automatically. A high rate raises the cost of borrowing but is refinanceable; the rent paid while waiting is not recoverable. Run both paths over your realistic holding period before deciding.

Can I avoid PMI with less than 20% down?

Lender-paid PMI trades the monthly premium for a higher permanent rate, and piggyback second loans carry their own rate risk. Both can be cheaper in a specific case; both should be compared on total cost, not on whether the word PMI appears.

Not financial advice. Mortgage FV Calculator is a software calculator, not a personal-finance product or advisory service. It computes standard financial functions and displays the results for your convenience. Nothing here constitutes, or is intended to constitute, financial, investment, tax, legal, mortgage, credit, or insurance advice. Always consult a qualified professional before making any financial decision.

First-time buyer putting 5% down

By Knobugsoft Engineering · Knobugsoft LLC · Last reviewed August 14, 2026 · Methodology

The question a 5%-down buyer actually faces is not "can I afford the mortgage" but "what does the whole payment look like, and what does waiting cost me?" This scenario walks through both with explicit numbers so you can replace them with your own.

Every figure below comes from the same calculation engine used by the site's calculators. Reproduce it by entering the assumptions in the mortgage calculator.

Assumptions used

Purchase price: $420,000
Down payment: $21,000 (5%)
Loan amount: $399,000
Rate / term: 6.75% fixed, 30 years
Property tax: 1.1% of value per year
Insurance: $1,800 per year
PMI rate: 0.55% of loan per year
Comparable rent: $2,450 per month

Illustrative figures, rounded. Replace them with your own in the calculators linked below — results will differ.

What the monthly payment really is

Principal and interest on $399,000 at 6.75% over 30 years is roughly $2,588. That is the number most listing sites show, and it is roughly two-thirds of the truth.

Add escrow and insurance and the picture changes: property tax at 1.1% of $420,000 adds about $385 a month, homeowners insurance about $150, and PMI at 0.55% of the loan about $183. The realistic all-in payment is close to $3,306.

• Principal & interest: about $2,588
• Property tax escrow: about $385
• Insurance escrow: about $150
• PMI: about $183 until 80% LTV
• Total: about $3,306 before any HOA dues

When PMI comes off, and what it is worth

PMI is not permanent. On the scheduled amortisation, the balance reaches 80% of the original $420,000 value in roughly the ninth year, and 78% — the automatic termination point — about a year later. Requesting cancellation in writing at 80% is worth roughly $2,200 a year from that point on.

Extra principal accelerates this materially, because cancellation tracks the balance rather than the calendar. An extra $200 a month pulls the 80% point forward by several years, and unlike most overpayment benefits, this one shows up immediately in cash flow rather than at the end of the loan.

Cash needed at the table

The down payment is the visible number; closing costs are the one that derails timelines. At 2%–5% of the price, expect $8,400–$21,000 on top of the $21,000 down payment, plus initial escrow funding of two to three months of tax and insurance.

Budget $34,000–$45,000 in total liquidity, and keep a separate reserve — underwriters look for it, and a first year of ownership without a repair fund is a stressful year.

Buying now versus saving to 20%

Waiting three years to reach 20% down avoids about $6,600 in cumulative PMI and lowers the eventual loan. Against that, you pay roughly $88,000 in rent over the same period and take price risk on both sides.

The honest way to settle this is a discounted comparison rather than a rule of thumb: put both paths through the rent-versus-buy model with a realistic appreciation assumption and your actual savings rate. PMI is a real cost, but it is usually a smaller number than three years of rent plus price movement.

Key takeaways

• Quote yourself the PITI-plus-PMI number, never principal and interest alone.
• PMI ends — plan the 80% LTV request date rather than treating it as permanent.
• Hold closing costs and reserves separately from the down payment in your savings plan.
• Test the wait-for-20% path as a full scenario, not as received wisdom.

Run it yourself

Each link opens the calculator pre-filled with this scenario's numbers.

Common questions

Is 5% down a mistake at a high interest rate?: Not automatically. A high rate raises the cost of borrowing but is refinanceable; the rent paid while waiting is not recoverable. Run both paths over your realistic holding period before deciding.
Can I avoid PMI with less than 20% down?: Lender-paid PMI trades the monthly premium for a higher permanent rate, and piggyback second loans carry their own rate risk. Both can be cheaper in a specific case; both should be compared on total cost, not on whether the word PMI appears.

Other scenarios

Unfamiliar with a term used here? See the mortgage glossary.

About the author

Quantitative finance engineering team, Knobugsoft LLC

Knobugsoft LLC builds financial calculation software. The same amortisation, time-value-of-money and discounted cash-flow engine that powers these guides serves the site's public API and is covered by an automated regression test suite run on every release.

• Amortisation and escrow modelling (principal, interest, taxes, insurance, PMI, HOA)
• Time value of money: future value, present value, NPV and IRR
• Rent-versus-buy and refinance break-even analysis

Every formula used on this site is documented on the methodology page. Spotted something wrong? Tell us — corrections are published with the review date updated.