← Job margin variance calculator
A finished job that cost more than the quote usually has one line that moved the most — a materials price that jumped, hours that ran long, or a small "other costs" line nobody watched. Finding that line by eye across three separate comparisons is slower than the arithmetic, and it is easy to fixate on the wrong one.
Open the free job margin variance calculator
Labor hours and dollars are different units. A job can run 4 hours over on labor and $45 over on materials at the same time — knowing which of those two is the bigger problem for the next quote takes comparing them side by side, not just a total dollar figure.
The largest movement is not always the total. Total cost variance combines materials and other costs; the single largest line can be either one of those, and it's the line worth reviewing first, not the combined total.
A record fades fast. The reasons behind an overrun — a supplier price change, an access delay, extra prep — are easiest to remember and log right after the job, before the next quote repeats the same estimate.
A job estimated at 16 labor hours, $420 in materials, and $80 in other costs actually ran 20 hours, $465 in materials, and $95 in other costs. Labor ran 4 hours over. Materials ran $45 over. Other costs ran $15 over. Total cost variance (materials plus other costs) is $60 above estimate. Comparing the three movements, materials is the largest single line to review — the $45 swing outweighs both the labor-hour overrun and the smaller other-costs line — so that's the assumption to revisit before quoting the next similar job.
Enter the estimated and actual figures for labor hours, materials, and other costs from the completed job. The calculator computes the variance on each line and reports total cost variance — actual materials and other costs minus estimated — in the same currency as the job, plus which single line moved the most.
Whichever line has the largest movement, reviewed line by line: labor-hour variance, materials variance, and other-cost variance are each measured in their own unit, and the largest single movement is flagged as the assumption most worth reviewing before the next similar quote.
Run the comparison immediately after the job closes, while the reasons for any overrun are still fresh, then copy the review into the job folder. The next time you quote similar work, check the assumption this report flagged as the largest mover before you repeat the same estimate.