You can use an online eligibility calculator or manually calculate your home loan eligibility. Lenders typically use a formula that limits your monthly housing costs to approximately 28% of your gross monthly income. To determine your eligibility, multiply your gross monthly income by 28%, subtract your existing debts and expenses, and divide the result by the current interest rate. However, to get a more accurate estimate based on your specific circumstances, you should speak with a lender or financial advisor.