Construction Loan Calculator
Connect the draw period with the permanent financing that follows completion.
Verify this calculatorMaintained
See what the result uses—and what it cannot know.
Sumvoro calculates deterministically from the visible inputs. It does not invent lender terms, local rules, market values, medical facts, or professional judgments.
- 1 · InputsCheck every entered value against the latest statement, quote, measurement, or official source.
- 2 · Formula
Construction interest uses an average drawn balance; permanent payment amortizes the completed balance. - 3 · SensitivityUse Insights to run a lower and higher case. If the conclusion changes easily, collect better information or leave more margin.
- 4 · ScopeThis tool is maintained and covered by automated calculation tests. Provider timing, rounding, and omitted facts can still change a real-world result.
- Formula release
- 2026.10-r4
- Release date
- October 10, 2026
- Review status
- Maintained
- Source review
- September 12, 2026
Optional readingLearn how this calculator works
How the construction loan calculator works
Estimate construction-period interest and permanent-loan payment.
Construction interest uses an average drawn balance; permanent payment amortizes the completed balance.
Read our calculation methodology and limitations.
Example
Start with the example scenario, then replace each clearly labeled field with values from your property, statement, quote, or project budget.
How does construction interest differ from the permanent payment?
- Land or existing balance
- $100,000
- Construction budget
- $450,000
- Cash contribution
- $110,000
- Construction rate
- 9 %
- Construction period
- 12 months
- Permanent-loan rate
- 6.75 %
- Permanent term
- 30 years
- Permanent monthly payment
- $2,853.83
- Estimated construction interest
- $20,250.00
- Peak financed balance
- $440,000.00
- Average modeled draw balance
- $225,000.00
The average-draw illustration is not a lender draw schedule. Budget delays and conversion terms separately.
These are fictional, editable assumptions—not market quotes or personal advice.
What affects the result
- Real draw schedules are not perfectly even.
- Rates can be variable during construction.
- Contingencies and overruns should be budgeted.
Frequently asked questions
What should I verify before relying on this?
Confirm property value, loan terms, costs, taxes, and local requirements with primary documents and the appropriate lender or professional.
Does Sumvoro save my property data?
The scenario stays locally in your browser unless you deliberately use a sharing or reporting action.