Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total interest carry through project
$106,192
Amount per draw
$500,000
Total cost (loan + interest)
$2,606,192
Average outstanding balance
$1,250,000
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter total construction loan ($).
- 2Enter number of draws.
- 3Enter months between draws.
- 4Enter interest rate (%).
- 5Read your total interest carry through project on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Construction loans disburse in draws tied to completion milestones rather than as a lump sum, and interest typically accrues only on the amount actually drawn, not the full committed loan amount, which means interest cost grows through the project as more of the loan gets disbursed. This calculator takes your total loan amount, a set of milestone draw percentages, the timing between draws, and the interest rate, then computes cumulative interest carry cost through the project — a number that matters for both developers sizing a project pro forma and contractors trying to understand the owner's cash position and payment reliability at each stage of the job. It assumes simple interest accrual on the outstanding drawn balance between draw dates, which is the standard method most construction lenders use for interim interest reserves.
Worked example
Using the values the calculator loads with:
Inputs
- Total construction loan: 2500000 $
- Number of draws: 5
- Months between draws: 2
- Interest rate: 8.5 %
Results
- Total interest carry through project: $106,191.78
- Amount per draw: $500,000.00
- Total cost (loan + interest): $2,606,191.78
- Average outstanding balance: $1,250,000.00
What each field means
Inputs
- Total construction loan ($)
- The total construction loan used in the calculation, measured in $. Starts at 2500000 $ so you have a working example on load.
- Number of draws
- The number of draws used in the calculation. Starts at 5 so you have a working example on load. Accepted range: 1–12.
- Months between draws
- The months between draws used in the calculation. Starts at 2 so you have a working example on load.
- Interest rate (%)
- The interest rate used in the calculation, measured in %. Starts at 8.5 % so you have a working example on load. Accepted range: 0–20 %.
Results
- Total interest carry through project
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Amount per draw
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total cost (loan + interest)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Average outstanding balance
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why does interest only accrue on the drawn amount, not the full loan?
Construction lenders disburse funds as work is completed and verified (often through an inspection or title company draw request process), so undrawn committed funds sit in the lender's reserve, not the borrower's account, and can't accrue interest cost. This is a key difference from a standard term loan where the full principal is disbursed and accruing interest on day one.
How does the number of draws affect total interest cost?
More draws spread out over the same total schedule generally reduces average outstanding balance timing slightly because funds get disbursed more incrementally rather than in large early chunks, but the effect is modest compared to the interest rate and total schedule length. The bigger levers are keeping the draw schedule tight to actual progress and negotiating rate, not the draw count itself.
What happens if a draw is delayed due to an inspection failure or documentation issue?
A delayed draw means the contractor may be financing that portion of the work out of pocket or through their own line of credit until the draw clears, which is a real cash flow risk distinct from the loan's interest cost itself. This is why contractors track draw request submission and approval timing closely and build a few days of buffer into their own cash flow projections.
Does this model account for an interest reserve built into the loan amount?
No — many construction loans include a separate interest reserve line item that gets drawn specifically to pay accruing interest so the borrower doesn't need out-of-pocket cash for interest during construction. If your loan includes an interest reserve, treat the total loan amount here as the hard construction cost portion only, not including that reserve.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Construction Draw Schedule Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/construction-draw-schedule
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/construction-draw-schedule" target="_blank" rel="noopener">Construction Draw Schedule Calculator — RevenueLab</a> (2026).</p>
Source: [Construction Draw Schedule Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/construction-draw-schedule) (2026).