http://www.ratehub.ca - Lenders calculate debt service ratios (GDS and TDS) before qualifying you for a mortgage. Drew Donaldson from Safebridge Financial walks through the calculations. <br /><br />0:39 Gross Debt Service Ratio (GDS) <br />1:34 Total Debt Service Ratio (TDS) <br /><br />ABOUT MORTGAGE MATH: <br />Whether you're a first-time homebuyer or a veteran homeowner, learning the ins and outs of the home buying process and the Canadian mortgage market can be a big undertaking. Produced by RateHub.ca and The Loop by Sympatico.ca, Mortgage Math is an all-new video series dedicated to giving viewers all of the information and tools needed to navigate through the world of mortgages and homeownership. <br /><br />Featuring some of RateHub.ca's best and brightest partners, you'll not only learn about seven different aspects of the home buying process -- like how to qualify for a mortgage, compare fixed and variable rates, and calculate CMHC insurance -- but also follow along as our experts perform the related calculations in real-time on a whiteboard.