Quick answer
Four unbilled scope-creep hours a week at $100 an hour cost $19,200 a year — and tracking software that recovers them returns $26,256 a year net of its $144 annual cost, about 182 times what it costs. The hours are already worked; the only question is whether they get billed.
How the Billable Hours Calculator works, step by step
Enter the hours you lose each week to unbilled scope creep, the hours you spend on manual time tracking and admin, your hourly rate and the monthly cost of tracking software. The calculator assumes 48 working weeks a year and turns those four inputs into the revenue you lose, the admin time software can return, and the net return on the software.
Lost revenue is the scope-creep line: unbilled hours × hourly rate × 48 weeks. Four hours a week at $100 an hour is $19,200 a year of work already done and never invoiced — the 'just one more quick change' that falls outside the statement of work and gets absorbed because nobody is counting.
The admin line is the time tracking software gives back. The calculator assumes good software saves 75% of your manual tracking time — the spreadsheet entries, the end-of-month reconstruction, the invoice arithmetic. Two manual hours a week become 1.5 hours saved, worth $7,200 a year at $100 an hour.
Net ROI is recovered revenue plus admin time saved, minus the software's annual cost. The ROI multiplier divides that net figure by the annual software cost, so a $26,256 net return on a $144 subscription is a 182x multiple. The multiple looks absurd because the subscription is trivial next to an hour of your rate. If the software cost were zero, the multiplier would be meaningless — the metric only works because the cost is real but small.
The deeper point is the record, not the software. Tracked hours turn a vague 'quick favor' into a priced change order: two hours at $100 is $200 added to the budget, agreed before the work starts. Even flat-fee freelancers need the record — without it, there is no way to know whether a $5,000 project took 20 hours or 100.
The formula
Net ROI = (unbilled scope-creep hours × hourly rate × 48) + (weekly admin hours × 75% × hourly rate × 48) − (monthly software cost × 12). ROI multiplier = net ROI ÷ annual software cost.
Worked example — try it on the calculator above
Worked example: 4 lost hours a week at $100 an hour
A freelancer loses 4 hours a week to unbilled scope creep, spends 2 hours a week on manual time tracking, charges $100 an hour and pays $12 a month for tracking software. Lost revenue is 4 × $100 × 48 = $19,200 a year. Admin time saved is 2 × 75% = 1.5 hours a week, worth 1.5 × $100 × 48 = $7,200 a year. The software costs $12 × 12 = $144 a year, so net ROI is $19,200 + $7,200 − $144 = $26,256 — 182 times the subscription. Recovering a single $100 hour a month would still cover the $144 annual cost more than eight times over.
Frequently Asked Questions
What is the true cost of scope creep?
Scope creep is the unbilled work that leaks out of a project: the extra revision, the 'quick change' outside the statement of work. At 4 hours a week and $100 an hour, it costs $19,200 a year. It is the most expensive line on this calculator because the hours are already worked — they are simply never invoiced.
Why should flat-fee freelancers track time?
Even when you charge flat fees, time tracking is how you know your effective hourly rate. A $5,000 project that takes 20 hours pays $250 an hour; the same project at 100 hours pays $50. Without tracked hours you cannot tell which projects are profitable, which clients cost you money, or what to quote next time.
How does time tracking software save administrative time?
Manual tracking means entering hours into spreadsheets, reconstructing forgotten days at month-end and building invoices by hand. Software logs time as you work and generates invoices from the log. This calculator assumes it saves 75% of manual admin time — 1.5 hours a week on the defaults, worth $7,200 a year.
What is a good ROI for time tracking software?
Most freelance time tracking software costs $10–$20 a month, so the bar is low: recovering one $100 billable hour a month covers a $12 subscription eight times over. At the defaults — 4 lost hours a week and 2 admin hours — the net return is $26,256 a year on $144 of cost, a 182x multiple.
Estimates, not advice. This calculator provides educational estimates based on the inputs you enter and the assumptions shown on this page. It is not financial, tax or investment advice, and it cannot see your full situation. Verify important figures against official sources, and consider a qualified professional for decisions about your own money. See our Disclaimer and Methodology.