Free Tool · Updated for 2026

Free Construction WIP & Over/Under Billing Calculator

Calculate percent complete, revenue earned and whether a job is overbilled or underbilled using the percentage-of-completion method. Built for general contractors, subcontractors, roofers and specialty trades.

Private by design. Your numbers never leave your browser, nothing is uploaded or stored.

Try an example:

Original contract value ($) Approved change orders ($) Estimated total cost to complete the job ($) Actual cost to date ($) Billed to date, including retainage ($)

Uses the cost-to-cost percentage-of-completion method. Run it for each open job to build a WIP schedule.

Over / under billing

billed to date minus revenue earned

Percent complete0%

Revenue earned to date$0

Estimated gross profit$0

Gross profit earned so far$0

How it works

How a WIP schedule measures over and under billing

Percent complete = actual cost to date ÷ estimated total cost (cost-to-cost method).
Revenue earned = contract value, including approved change orders, × percent complete.
Over or under billing = billed to date − revenue earned.

Result	What it means	Balance sheet
Overbilled	You billed ahead of the work performed	Current liability (“billings in excess of costs”)
Underbilled	You performed more work than you billed	Current asset (“costs in excess of billings”)

Banks and surety companies review WIP schedules before approving credit lines and bonding. A job that is consistently underbilled, or where costs outrun the estimate, is an early warning sign. Read the full guide: construction WIP schedules explained.

For contractors

Job costing makes the WIP schedule accurate

A WIP schedule is only as good as the job costs behind it. Every labor hour, material purchase and subcontractor bill has to be coded to the right job. See our construction bookkeeping services and the construction job costing guide.

More free tools

Keep going

Profit Margin Calculator Cash Flow Forecast Break-Even Calculator Construction Bookkeeping Roofing Bookkeeping All Free Tools

FAQ

WIP and billing questions

What is a WIP schedule in construction?+

A work-in-progress schedule lists every open job with contract value, estimated cost, cost to date, percent complete, revenue earned and billings. It shows whether each job is overbilled or underbilled and how much profit has been earned so far.

Is overbilling bad?+

Not necessarily. Billing slightly ahead of the work helps cash flow. But overbillings are a liability: you owe that work. Spending them as profit leaves you short of cash later in the job.

What does underbilling mean?+

You have done more work than you have invoiced. It is recorded as an asset, but large or growing underbillings can mean missed billing, unapproved change orders or a job running over budget.

How often should a contractor update the WIP schedule?+

Most contractors update it monthly, at the same time as the books are closed, so job profit and billing problems show up while there is still time to act.

Want a monthly WIP schedule done for you?

Book a free consultation. We job-cost every bill and payroll hour and deliver a WIP schedule your bank and bonding company can trust.

Book Free Consultation Call +1 (832) 240-0830