Down Payment Calculator
A down payment calculator helps you determine how much to save for a home purchase and how your down payment affects monthly payments, total interest, and PMI requirements.
Down Payment Requirements by Loan Type
| Loan Type | Minimum Down | PMI Required | Best For | Conventional3-5%Yes, if <20%Good credit (620+) FHA3.5%Yes (MIP)Lower credit (580+) VA0%NoVeterans/active military USDA0%NoRural areas Jumbo10-20%VariesHigh-value homes
Down Payment Impact on $300,000 Home
Down PaymentAmountLoanMonthly P&I (7%)PMITotal Monthly 3%$9,000$291,000$1,936$243$2,179 5%$15,000$285,000$1,896$238$2,134 10%$30,000$270,000$1,797$169$1,966 | 20% | $60,000 | $240,000 | $1,597 | $0 | $1,597 |
Down Payment Calculator Implementation
``javascript
function calculateDownPayment(homePrice, downPaymentPercent, rate, termYears) {
const downPayment = homePrice * (downPaymentPercent / 100);
const loanAmount = homePrice - downPayment;
const monthlyRate = rate / 100 / 12;
const payments = termYears * 12;
const monthlyPayment = loanAmount * monthlyRate / (1 - Math.pow(1 + monthlyRate, -payments));
// Estimate PMI (0.5-1% of loan annually)
const pmi = downPaymentPercent < 20 ? (loanAmount * 0.01) / 12 : 0;
const totalInterest = (monthlyPayment * payments) - loanAmount;
return {
downPayment: downPayment.toFixed(2),
loanAmount: loanAmount.toFixed(2),
monthlyPayment: monthlyPayment.toFixed(2),
pmi: pmi.toFixed(2),
totalPayment: (monthlyPayment + pmi).toFixed(2),
totalInterest: totalInterest.toFixed(2)
};
}
console.log(calculateDownPayment(300000, 20, 7, 30));
``
Saving for a Down Payment
At $500/month savings, reaching 20% down on a $300,000 home takes 10 years. Consider whether paying PMI to buy sooner makes sense based on home appreciation in your market.