Debt Service Ratio Calculator

GDS / TDS

Understand how lenders measure your ability to carry debt. GDS and TDS are core underwriting metrics for all mortgage types.

Monthly Expenses & Income

Monthly Mortgage Payment

Principal + interest (or interest only)

Property Tax / Month

Annual tax ÷ 12

Heating Cost / Month

Condo Fee / Month

50% counted in GDS/TDS

Other Monthly Debts

Car loans, credit cards, student loans

Gross Monthly Income

Before-tax household income

GDS

Gross Debt Service

35.00%

High

0%Guideline: 32%100%

GDS measures housing costs as a share of income. Standard guideline is 32% for A-lenders; private lenders may allow higher.

TDS

Total Debt Service

40.00%

Acceptable

0%Guideline: 44%100%

TDS includes all debt payments. Standard guideline is 44%. Private lenders focus more on equity and exit strategy than TDS ratios.

GDS Guidelines

Under 28%Strong

28–32%Acceptable

Over 32%High — Private lender territory

TDS Guidelines

Under 38%Strong

38–44%Acceptable

Over 44%High — Private lender territory

This calculator provides estimates only and does not constitute a mortgage offer, pre-approval, or commitment. Actual rates, terms, and eligibility depend on a full review of your application. Consult a licensed mortgage professional for personalized advice.