Construction Loan Calculator

Estimate the cost of a construction loan with interest-only payments during the build.

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Construction Loan

Enter the construction budget and loan details.

Total construction loan cost
$0
Interest during build: $0
Loan amount
$0
Interest-only payment (mo)
$0
Total interest during build
$0
Permanent monthly payment
$0
Total cost (build + perm)
$0
Total interest over life
$0

Worked example

With the default inputs shown below, this calculator returns the following results:

InputValue
Total construction cost ($)$300,000
Down payment ($)$60,000
Construction loan rate (%)7.5%
Construction period (months)12
Permanent loan rate (%)6.5%
Permanent loan term (years)30 years
ResultValue
Total construction loan cost$1,500
Loan amount$240,000
Interest-only payment (mo)$1,500
Total interest during build$18,000
Permanent monthly payment$1,517
Total cost (build + perm)$564,107

Values shown are produced by this page in your browser; change any input to update them.

How to use the Construction Loan

  1. Total construction cost ($) — default $300,000
  2. Down payment ($) — default $60,000
  3. Construction loan rate (%) — default 7.5%
  4. Construction period (months) — default 12
  5. Permanent loan rate (%) — default 6.5%
  6. Permanent loan term (years) — default 30 years
  7. Press Calculate to update the results instantly.

Frequently asked questions

The lender releases funds in stages as the build progresses and charges interest only on what has been drawn. Once the house is finished the loan converts to a permanent mortgage.
Usually 1-2 percentage points above a standard mortgage, because the lender carries more risk while the property is incomplete.
Plan for 10-20% above the contract price. Overruns are so common that a contingency is treated as part of the build cost, not a luxury.

Sources & references