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All calculatorsMethodology

Debt-to-Income Calculator

Calculate front-end and back-end debt-to-income ratios, the largest housing payment your chosen DTI limits allow, and the loan amount that payment supports.

Interactive calculator · Method DEBT-TO-INCOME-1.0 · Last reviewed: 2026-11-04

Calculate your scenario

Front-end ratio = monthly housing payment ÷ gross monthly income × 100; back-end ratio = (housing payment + other monthly debt payments) ÷ gross monthly income × 100.

Your inputs

Try an example

Default worked example. Edit the inputs to calculate your scenario.

Default worked example

Front-end ratio (housing ÷ income) 26.67%
Back-end ratio (all debts ÷ income) 36.67%
Max housing payment by front-end limit $2,100.00
Max housing payment by back-end limit $1,950.00
Max housing payment (lower of the two) $1,950.00 (back-end limit binds)
Loan amount that payment supports $245,226.77

Housing $2,000.00 ÷ income $7,500.00 = 26.67%; ($2,000.00 + $750.00) ÷ $7,500.00 = 36.67%. Allowed payment $1,950.00 − $400.00 taxes and insurance = $1,550.00 principal and interest → $245,226.77.

How to use the calculator

Enter gross income, the proposed full housing payment and each monthly debt payment. Then enter the front-end and back-end limits you want to test, plus a rate, term and monthly taxes and insurance to turn the allowed payment into a loan amount.

What the result means

On $7,500 a month, a $2,000 housing payment is 26.67% front-end and 36.67% back-end with $750 of other debts. The 36% back-end limit binds at $1,950, which after $400 of taxes and insurance supports about $245,227 at 6.5% over 30 years.

Formula and units

Front-end ratio = monthly housing payment ÷ gross monthly income × 100; back-end ratio = (housing payment + other monthly debt payments) ÷ gross monthly income × 100. Annual income is divided by 12. Max payment by the front-end limit = income × limit; by the back-end limit = income × limit − other debts; the lower one binds. Loan amount = (that payment − taxes, insurance and HOA) × (1 − (1 + r)^−n) ÷ r, with r = rate ÷ 12 and n = years × 12 (payment × n when the rate is 0).

Worked examples

$7,500 a month with a $2,000 payment and $750 of debts: Gross income (before tax): 7500 $; Proposed monthly housing payment (principal, interest, taxes, insurance, HOA): 2000 $/month; Car loan payment: 400 $/month; Student loan payment: 250 $/month; Credit card minimum payments: 100 $/month; Other monthly debt payments: 0 $/month; Front-end (housing) limit to test (example 28%): 28 %; Back-end (total debt) limit to test (example 36%): 36 %; Mortgage rate for the loan estimate (example): 6.5 % APR; Loan term: 30 years; Monthly taxes, insurance and HOA in the housing payment: 400 $/month; Income entered as: monthly.
Example result: Front-end ratio (housing ÷ income): 26.67%; Back-end ratio (all debts ÷ income): 36.67%; Max housing payment by front-end limit: $2,100.00; Max housing payment by back-end limit: $1,950.00; Max housing payment (lower of the two): $1,950.00 (back-end limit binds); Loan amount that payment supports: $245,226.77.

$120,000 a year tested against 31% and 43% limits: Gross income (before tax): 120000 $; Proposed monthly housing payment (principal, interest, taxes, insurance, HOA): 2500 $/month; Car loan payment: 600 $/month; Student loan payment: 0 $/month; Credit card minimum payments: 0 $/month; Other monthly debt payments: 0 $/month; Front-end (housing) limit to test (example 28%): 31 %; Back-end (total debt) limit to test (example 36%): 43 %; Mortgage rate for the loan estimate (example): 0 % APR; Loan term: 15 years; Monthly taxes, insurance and HOA in the housing payment: 500 $/month; Income entered as: annual.
Example result: Front-end ratio (housing ÷ income): 25%; Back-end ratio (all debts ÷ income): 31%; Max housing payment by front-end limit: $3,100.00; Max housing payment by back-end limit: $3,700.00; Max housing payment (lower of the two): $3,100.00 (front-end limit binds); Loan amount that payment supports: $468,000.00.

Limitations and common mistakes

Ratios from your entries only; this is not a lending decision or prequalification. Lenders set their own limits, count income and debts by their own rules, and may add mortgage insurance, reserves or credit requirements. The 28% and 36% defaults are examples to edit. Living costs that are not debt payments are not part of DTI.

Using take-home pay instead of gross income, or leaving taxes and insurance out of the housing payment, makes the ratios look different from how lenders usually define them.

Sources and assumptions

Method DEBT-TO-INCOME-1.0; last formula review 2026-11-04. Sources and their supported claims. Calculation methodology.