Gross Debt Servicing or Gross Debt Servicing Ratio.
This is the percentage of your gross monthly household income that covers your housing costs. To calculate this, you divide your monthly housing costs by your gross monthly income. You typically want your housing costs to be at or under 35% of your gross monthly income.
If you're renting, your GDS is your monthly rent cost divided by your gross monthly income. If you own your home, your GDS will include your monthly mortgage payment, monthly property taxes, and monthly heating bill divided by your gross monthly income.