Construction Mortgage Calculator
See what carrying a draw-based construction mortgage actually costs, stage by stage, and what the payment looks like once it converts to a standard mortgage after completion.
Total interest during construction
$7,125
Averaging about $1,187.50/month, interest-only, over the 6-month build. Once complete, the mortgage converts to $1,623.67/month amortizing.
Draw-by-draw schedule
| Draw | Month | Cumulative drawn | Monthly interest-only |
|---|---|---|---|
| 1 | 1 | $57,000.00 | $356.25 |
| 2 | 2 | $114,000.00 | $712.50 |
| 3 | 3 | $171,000.00 | $1,068.75 |
| 4 | 4 | $228,000.00 | $1,425.00 |
| 5 | 5 | $285,000.00 | $1,781.25 |
The draw schedule above assumes equal-sized draws released at evenly spaced intervals. Real draw schedules are milestone-based (foundation, framing, lock-up, drywall, final) and vary by lender and project — this models the cash-flow shape, not your lender's specific schedule.
How draw mortgages actually work
For the full walkthrough of qualification requirements, timeline, and common mistakes, read the Construction Mortgage Guide. To see how much you can actually borrow before modeling the carrying cost, start with the ADU Financing Calculator.