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
Peak cash you fund yourself
$1,500
Deposit collected
$15,000
Each milestone invoice
$11,250
Deposit % needed to stay cash-neutral
28%
Project cash position at close
$27,000
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
Got your number — what next?
Pick one, it takes 20 secondsHow to use this
- 1Enter project fee ($).
- 2Enter project length (months).
- 3Enter deposit taken upfront (%).
- 4Enter total delivery cost ($).
- 5Enter client payment terms (days).
- 6Read your peak cash you fund yourself on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
A project can be profitable on paper and still drain your bank account if you fund delivery for two months before the first invoice clears. This calculator lays a deposit percentage and milestone schedule against your monthly delivery cost and payment terms, and reports the deepest negative cash position the project reaches — the amount of your own money you're lending the client — along with the deposit percentage that would keep the project cash-neutral. Most agencies find a 40-50% deposit on short projects, or monthly-in-advance billing on retainers, eliminates project financing entirely.
Worked example
Using the values the calculator loads with:
Inputs
- Project fee: 60000 $
- Project length: 4 months
- Deposit taken upfront: 25 %
- Total delivery cost: 33000 $
- Client payment terms: 45 days
Results
- Peak cash you fund yourself: $1,500.00
- Deposit collected: $15,000.00
- Each milestone invoice: $11,250.00
- Deposit % needed to stay cash-neutral: 28%
- Project cash position at close: $27,000.00
What each field means
Inputs
- Project fee ($)
- The project fee used in the calculation, measured in $. Starts at 60000 $ so you have a working example on load.
- Project length (months)
- The project length used in the calculation, measured in months. Starts at 4 months so you have a working example on load. Accepted range: 1–24 months.
- Deposit taken upfront (%)
- The deposit taken upfront used in the calculation, measured in %. Starts at 25 % so you have a working example on load. Accepted range: 0–100 %.
- Total delivery cost ($)
- The total delivery cost used in the calculation, measured in $. Starts at 33000 $ so you have a working example on load.
- Client payment terms (days)
- The client payment terms used in the calculation, measured in days. Starts at 45 days so you have a working example on load.
Results
- Peak cash you fund yourself
- 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.
- Deposit collected
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Each milestone invoice
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Deposit % needed to stay cash-neutral
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Project cash position at close
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What deposit should I ask for?
25-50% is standard for project work, and clients rarely object when it's framed as scheduling the resource rather than as distrust. For first engagements with an unknown client, a higher deposit is also your credit check.
Milestones or monthly billing?
Monthly billing is smoother for cash and simpler to administer; milestone billing suits clients who need deliverable-linked approvals. The cash difference usually comes down to whether milestones are evenly spaced or back-loaded — back-loaded milestones are where exposure builds.
Why does payment terms lag matter so much?
Because it shifts every invoice one to two months to the right while your payroll runs on schedule. The same project with net-15 rather than net-60 terms can cut peak exposure by more than half without any change to the fee or deposit.
Is funding a client's project ever acceptable?
Occasionally, for a strategic account with strong credit — but price it. If you're carrying $40k for two months, that's a real financing cost that belongs in the fee, not a free service.
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
Days Sales Outstanding Cost Calculator
Price what slow-paying clients cost you in tied-up working capital.
Services Business Cash Runway Calculator
Account for unpaid invoices and payment terms to get a real runway number.
Project Effective Hourly Rate Calculator
Divide the real project fee by every hour it consumed, including sales and admin.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Project Deposit & Milestone Billing Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/agency-deposit-structure
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/agency-deposit-structure" target="_blank" rel="noopener">Project Deposit & Milestone Billing Calculator — RevenueLab</a> (2026).</p>
Source: [Project Deposit & Milestone Billing Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/agency-deposit-structure) (2026).