Tekin Works › Free tools
Free calculators for the work
that has to be right
Each of these answers one question properly and then tells you where it stops. No account, no email, no signup. They run entirely in your browser — you can disconnect from the internet and they will still work, and nothing you type is sent anywhere or seen by me.
Fringe credit & the overtime floor
Certified payroll · public-works contractors
Test one worker's week against the wage determination — then watch what closing a fringe gap with cash does to the overtime rate. That second half is the part a spreadsheet cannot see.
Open it →Progress billing & retainage
Progress billing · subcontractors and GCs
The nine lines of a payment application, with retainage held at different rates on completed work and stored materials — and the step-down at substantial completion that spreadsheets almost never implement correctly.
Open it →What a deduction really costs
Retail deductions · brands selling into chains
A deduction is not a discount — it comes out of margin, not revenue. This prices the shipping needed to replace one, and finds the size below which disputing it costs more than it recovers.
Open it →Condo reserve funding, 10% or 15%
Condo associations · managers · boards
The replacement reserve floor rises from 10% to 15% for loan applications dated on or after 4 January 2027. This checks a budget against the floor that applies on the application date — and against the reserve-study route that most summaries miss.
Open it →Why these are free, and what the catch is
The catch is on the page already: each one is the small version of a system I sell. The calculator checks one worker, one period, one deduction. The paid system does it for the whole book, carries it forward month to month, produces the form, and gives the other side somewhere to look at it.
If the small version is all you needed, take it — that is a perfectly good outcome and there is nothing to unsubscribe from. If it makes it obvious that the spreadsheet is not going to hold, the tour of the finished system is one click away, has a demo login printed on it, and does not ask you to book a call.
Every one of them says what it does not do, in a section you do not have to go looking for. A tool that only ever produces the flattering answer does not get trusted, and it should not be.
The finished systems
Seven of them, all live, all loaded with demonstration data, each with a written walkthrough rather than a sales call.