The size of the down payment influences almost every part of the mortgage. A larger down payment reduces the loan amount, which lowers the monthly principal-and-interest payment and the total interest paid over time. It also improves the loan-to-value ratio, often unlocking a better interest rate from the lender. Crossing the 20% threshold on a conventional loan eliminates private mortgage insurance entirely, removing a cost that can run $100–$300 or more each month.
On the other side, tying up more cash in the house means less money available for emergency reserves, closing costs, moving expenses, or other investments. Some buyers prefer to put down 5% or 10%, accept temporary PMI, and keep liquidity. Others stretch to reach 20% so the monthly payment stays as low as possible and the insurance disappears from day one. There is no single correct answer; it depends on your overall financial picture and risk tolerance.
Test both approaches with the mortgage calculator and the amortization calculator. Enter the same home price with 5%, 10%, and 20% down and compare the monthly payments, total interest, and the point at which PMI would drop off. For FHA loans the insurance rules are different, so check the FHA loan calculator as well.
Gift funds, down-payment assistance programs, and employer assistance can help bridge the gap without draining personal savings. Whatever percentage you choose, make sure the remaining cash reserves feel comfortable. A slightly higher payment with a solid emergency fund is usually safer than a rock-bottom payment that leaves you one surprise repair away from trouble.