Conventional loans come in two main types: fixed-rate or adjustable-rate. These loans tend to have stricter requirements than government-backed loans, such as: a minimum score of 620 to qualify however, to secure the lowest interest rate and the best deal, you’ll want a 740 or higher. In most cases your debt-to-income ratio can’t exceed 45%. Minimum down payment starts at 3% for first time home buyers and 5% for non-first-time buyers.