If your combined household income is $8,000 per month, the maximum monthly repayment for an HDB loan is capped at 30% of your gross monthly income.
This means your maximum monthly HDB loan repayment can be up to $2,400. The actual loan amount you can take will depend on the loan tenure, prevailing HDB interest rate (currently 2.6%), and your age. HDB will use these factors to determine the maximum loan quantum you are eligible for.