Free calculator · Business
Job Costing Calculator
The job is done and the invoice is paid. But did you actually make what you thought you would? Put in what you charged and what it really cost, and find out where the profit went.
The short version
Job costing is checking a finished job against your quote. Take what you charged, subtract what the job actually cost in labour, materials and extras, and you have your real profit. Compare that with the profit you quoted for, and you learn exactly where jobs make or lose you money.
Actual profit = Price charged − Actual costs • vs quote = Actual profit − Quoted profit
The job you think made money often did not
Every trade has done it. A job feels like a good one, the invoice is a decent size, so you assume it was profitable. Then you actually add up the hours you spent and the materials you bought, and the profit is half what you expected. Or gone.
Job costing is the five-minute habit that catches this. Do it on your jobs for a month and patterns jump out fast, and they are almost always the same two culprits.
Labour overruns are the number one profit killer. The hours creep, nobody logs it, and the job that was priced at 16 hours quietly takes 22. Materials are second: bought more than you quoted, or prices moved.
What to do with what you find
- Feed it back into your quotes. If this type of job always runs two hours over, price two hours in next time.
- Find the pattern, not the one-off. One bad job is bad luck. The same leak on every job is a pricing problem.
- Know your good work. Costing also shows which jobs make the most, so you can go and win more of those.
Questions tradespeople ask
What is job costing?
Job costing is working out what a specific job actually cost you and comparing it to what you charged, so you know the real profit. Done regularly, it shows which jobs and which types of work genuinely make you money, and where your quotes are off.
What is the difference between a quote and job costing?
A quote is your estimate before the work, based on what you think it will cost. Job costing is the reckoning afterwards, based on what it actually cost. The gap between the two is the most useful number in your business, because it tells you how good your quoting really is.
What counts as the cost of a job?
The labour hours spent times what that labour costs you, plus the materials you bought for it, plus any extras like hire, subcontractors, disposal or putting right mistakes. It does not include general overheads like your van or insurance, those are covered by your margin across all jobs.
What if a job lost money?
It happens, and it is far better to know than to guess. Look at where it went: was the quote too low, did labour run over, did materials cost more, or did the scope creep without a price change. Fix that one thing in how you quote or manage the next job.
How often should I cost my jobs?
Ideally every job, at least the bigger ones, while the numbers are fresh. If that is too much, cost a sample each month. Even a handful will reveal where your profit is leaking.
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