Calculator
What a rained out morning actually costs
Enter your crew size, burdened rate, idle equipment and daily general conditions to see the real cost of a weather day and of every weather day you failed to document.
Free tools
Weather day calculators for commercial job sites
Two free tools that put numbers on the part of the job nobody bids accurately: what a rained out morning costs and how many days you are owed beyond the baseline.
Weather arguments on commercial work usually stall on arithmetic. The superintendent knows the crew went home. The project manager knows the general conditions kept running. The owner's scheduler knows the contract already anticipated some adverse weather. Nobody has put the three numbers side by side, so the conversation stays about whether it rained hard enough, which is the least productive version of the discussion.
These calculators are deliberately plain. The first one converts a rained out morning into a dollar figure using your own crew size, burdened rate, idle equipment and daily general conditions, then shows what a handful of undocumented days costs across a year. The second one takes your baseline weather day allowance and your actual qualifying days, adds the dry out days that follow, and shows the calendar extension you should be requesting along with how many of those days are exposed by late notice. Change the inputs to match your job and the numbers move with you.
Calculator
How many calendar days are you actually owed
Put your baseline allowance next to the qualifying days you logged, add the dry out days that followed, and see the extension you should request and how much of it late notice puts at risk.
Working document
The weather day log and notice template
A one page fill in record for the morning it rains, built so a reviewer who was never on your site can follow the day from the first gauge reading to the notice that went out.
Why the weather day arithmetic is open to anyone
Superintendents already run these numbers by hand, usually on the back of a submittal log at the gate. You count fourteen workers who showed up and produced nothing, guess at a burdened rate, add the excavator and the two lifts still on rent, and then leave out the trailer, the temporary power, the dumpster service and the salaried supervision that billed for the whole calendar day anyway. The second sum is worse: a project engineer tallying qualifying days against the monthly anticipated weather day table on a legal pad in the trailer, usually in October, for a month that got wet back in April.
Neither of those sums belongs behind a sign up form, so there is not one. Nothing is stored and nothing is sent. Run the rain day cost before your next owner meeting and you can quote one defensible figure instead of arguing about how hard it rained. Run your baseline allowance, your logged qualifying days and your dry out ratio through the estimator and you will know this month whether you have already passed the table and how many of those days late notice puts at risk. Even if you never subscribe to anything here, those two numbers change how a schedule extension request gets argued.
The number holds only if the day behind it does
Whatever the calculators just told you about the cost of a lost morning or the calendar days you are owed, an owner's scheduler will ask where the precipitation figure came from, which controlling activities stopped and when written notice went out. A twenty minute walkthrough shows those four things being captured on the morning it rains rather than reconstructed from a phone gallery a year later. Bring your own inputs and we will use your job, not a sample one.