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Free Construction Payment & Billing Tools for Contractors
Progress payments, retainage and the cash gap it leaves behind — calculated the way your contract actually works, in your browser, without an account.
The tools
Built around how contractors actually get paid
Eight tools covering what to bill, what is being withheld, and what it does to your cash. Each shows the full breakdown, not just an answer — so you can check it against your application line by line before you submit.
Progress Payment Calculator
Work out exactly what to bill this period from percent complete, change orders, stored materials and retainage.
Gross earned − Retainage − Previous payments
AIA-Style Payment Application
The figures a G702-style application needs, with separate retainage rates on completed work and stored materials.
Earned less retainage − Previous certificates
Retainage Calculator
See what is being held back, what has been released, and the cash gap you are funding in the meantime.
Gross earned × Retainage %
Construction Draw Calculator
What to draw against work performed since the last one — the contractor's side, not the lender's.
Gross draw − Retainage − Previous draws
Change Order Calculator
Price added work with overhead, profit and tax stacked in the right order — and see markup and margin side by side.
((Cost + Overhead) + Profit) + Tax
Payment Schedule Calculator
Build a milestone schedule with retainage and net payments, in a column that sums to the contract exactly.
Contract allocated across milestones
Construction Cash Flow Calculator
Month-by-month balance including retainage and payment lag. Finds the lowest point before it finds you.
Cash in − Cash out, cumulative
Late Payment Calculator
Interest and fees on an overdue invoice — daily, weekly, monthly or flat, with grace periods handled properly.
Invoice + Interest + Late fee
Why it exists
Most calculators give you a number
This one shows the arithmetic, because the number is going on an application somebody is going to check.
Nothing gated behind signup
Everything runs in your browser. Nothing you type is uploaded, and there is no account wall in front of an answer you need right now.
Exact money arithmetic
Decimal maths with explicit half-up rounding, never floating point. Figures match a properly configured accounting system to the cent.
The assumptions are written down
Every page publishes its formulas, a worked example, and the mistakes that most often produce a wrong application.
How it works
Four steps, none of them a signup form
01
Pick the tool that matches the question
Billing this month is a progress payment. Working out what is being withheld and what it costs you is retainage. Each page states plainly what it answers.
02
Enter the numbers from your contract
Every field is prefilled with a realistic example so you can see the shape of the answer before you replace it with your own figures.
03
Read the full breakdown, not just the total
Revised contract, earned work, retainage and remaining scope are all shown, so a disputed line on an application is easy to trace back.
04
Save it when it is worth keeping
A free account stores calculations against projects and customers. Nothing is gated behind it until you want that history.
Free and Pro
The calculators stay free
Pro exists for the work that happens after the calculation — keeping it, reusing it, and turning it into a document somebody signs.
Free
- Every calculator, without an account
- Full breakdown and worked examples
- Print and basic PDF
Pro
- Saved calculations, projects and customers
- Payment applications and change orders
- Retainage tracking across periods
- Branded PDFs and CSV export
Pricing is published on the pricing page when Pro opens.
FAQ
Common questions
Are the construction payment calculators free?
Yes. Every calculator is free and needs no account. They run in your browser, so nothing you type is uploaded or stored anywhere.
Do I need to sign up to calculate?
No. Signup only becomes useful when you want to save calculations, reuse project details or generate branded PDFs. Calculating, printing and reading the breakdown never require an account.
How accurate are the calculations?
Calculations use decimal arithmetic with explicit half-up rounding rather than floating point, and each formula is verified against a fixed set of test vectors before release. That means the figures match what a properly configured accounting system produces, to the cent.
Can I use these for AIA-style payment applications?
The progress payment calculator produces the figures a G702-style application needs — revised contract, work completed, stored materials, retainage and current payment due. BuildPayTools is not affiliated with or endorsed by The American Institute of Architects, and does not reproduce AIA forms.
Do the tools handle retainage correctly?
Retainage is applied to cumulative gross earned before previous payments are deducted, which is the standard order on a progress billing. Rates and release schedules vary by contract and jurisdiction, so enter the rate your contract specifies rather than assuming a standard figure.
Who is BuildPayTools for?
General contractors, subcontractors, builders, remodelers, estimators and project managers in the United States — anyone who has to justify a number on a payment application.
Work out what to bill this month
Free, instant, and no account required.