Generally, lenders will allow you to borrow up to around 80 to 90% percent of your available equity (the amount of value you have in your house) depending on the lender, your credit score, and income. For example, let's say you bought your house for $350,000 and you have paid off $175,000 of a $300,000 mortgage, meaning you still have $125,000 to pay back. A recent appraisal values your house at $500,000 now. You would calculate your current equity in your house like this: $500,000 - $125,000 = $375,000. Your specific lender will have a percentage of that $375,000 that they'll allow you to borrow.