Second Home Mortgage Calculator
Calculate monthly payments on a second home mortgage. Covers deposit requirements, stamp duty (UK), interest rates, and worked examples for UK and US buyers.
A second home mortgage requires a minimum 10–20% deposit and typically carries an interest rate 0.25–0.75% higher than a primary residence mortgage. Monthly payment = Loan amount × [r(1+r)^n] ÷ [(1+r)^n − 1], where r = monthly interest rate and n = number of monthly payments.
How a Second Home Mortgage Differs from a Primary Mortgage
A second home mortgage is used to finance a property you intend to use personally (holiday home, weekend retreat) but is not your main residence. Lenders treat these as slightly higher risk than primary mortgages because borrowers are more likely to default on a second home under financial stress.
| Feature | Primary Residence | Second Home |
|---|---|---|
| Minimum deposit (UK) | 5–10% | 15–25% |
| Minimum deposit (US) | 3–20% (FHA: 3.5%) | 10–20% |
| Interest rate | Baseline | +0.25–0.75% above primary |
| Stamp Duty (UK) | Standard rates | +3% surcharge |
| US mortgage interest | Deductible | Deductible if used personally |
| Rental income | N/A | Allowed part of the year |
Monthly Payment Formula
Monthly Payment = P × [r(1+r)^n] ÷ [(1+r)^n − 1]
Where:
- P = Principal loan amount (property price minus deposit)
- r = Monthly interest rate = Annual rate ÷ 12
- n = Total monthly payments = Loan term in years × 12
Worked Examples
Example 1 — UK Second Home Purchase
- Property value: £350,000
- Deposit: 20% = £70,000
- Loan amount (P): £280,000
- Interest rate: 4.75% annual → r = 0.3958% per month
- Term: 25 years → n = 300 payments
- Monthly payment ≈ £1,567
- Additional UK cost: Stamp duty surcharge = 3% extra = £10,500
Example 2 — US Second Home Purchase
- Property value: $400,000
- Deposit: 15% = $60,000
- Loan amount: $340,000
- Interest rate: 7.25% (second home premium) → r = 0.6042%
- Term: 30 years → n = 360 payments
- Monthly payment ≈ $2,319
FAQ
How much deposit do I need for a second home mortgage?
In the UK, most lenders require 15–25% deposit for a second home. In the US, the minimum is typically 10%, but 20% avoids private mortgage insurance (PMI). The higher the deposit, the better the interest rate offered.
Can I use equity from my first home to fund the deposit?
Yes. You can remortgage your primary residence (UK) or take a cash-out refinance (US) to release equity and use it as the deposit on a second property. This effectively uses your home's increased value to fund the new purchase.
What is the interest rate difference for a second home mortgage?
Second home mortgage rates are typically 0.25–0.75% higher than equivalent primary residence rates. This premium reflects the increased default risk lenders associate with non-primary properties.
Do I pay extra stamp duty on a second home in the UK?
Yes. HMRC charges an additional 3% stamp duty surcharge on second homes and buy-to-let properties in England and Northern Ireland. For a £350,000 property, this means approximately £10,500 in additional stamp duty on top of standard rates.
What is the debt-to-income (DTI) requirement for a second home mortgage?
Most lenders require a total DTI ratio of 43% or below, meaning your total monthly debt payments (including both mortgages) should not exceed 43% of your gross monthly income. Some lenders allow up to 50% DTI with compensating factors.
Can I rent out my second home?
Yes, for part of the year, subject to lender terms. In the US, you can rent out a second home for up to 14 days per year tax-free without it being reclassified as an investment property. Beyond 14 days, different tax rules apply.