Job Costing Calculator
Track actual costs against your quote — see your real profit on every job.
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Frequently Asked Questions
What is job costing?
Job costing is the process of tracking all actual costs incurred on a specific job — labour, materials, and overheads — and comparing them against what you originally quoted or estimated. It tells you whether you made a profit on that job, and by how much. Without job costing, you're flying blind: you might be winning work but losing money on every job.
How often should I review job costs?
Ideally after every single job, no matter how small. Record actuals while they're fresh — same day is best. Then review patterns weekly: are you consistently over on labour for certain job types? Are material costs creeping up? Monthly trend reviews help you spot systemic quoting problems before they drain your cash flow.
What's a good profit margin for a tradesman?
A healthy net profit margin for a UK tradesperson is typically 20–35% after all costs including your own labour. Anything below 15% is tight and leaves little room for slow weeks, van breakdowns, or late payments. If your margins are consistently below 20%, revisit your hourly rate — you're likely undercharging for your time.
Why are my actual costs always higher than quoted?
The most common culprits are: underquoting labour hours (jobs always take longer than you think), material waste and offcuts you didn't price in, unexpected snags discovered on site, and rising material costs between quote and job start. Build a contingency buffer of 10–15% into every quote to absorb the unexpected.
Can I use this for CIS jobs?
Yes. When costing CIS jobs, factor in the CIS deduction on your labour income (20% standard rate, or 30% if unverified). Your quoted labour figure should reflect what you'll actually receive net of the deduction, or you should account for it separately in your cash flow planning. Materials are not subject to CIS deduction.
Should I include VAT in job costing?
Always cost jobs net of VAT. If you're VAT registered, VAT is a pass-through — you collect it from the customer and pay it to HMRC, so it's not your revenue or cost. If you're not VAT registered, your material costs will include VAT (which you can't reclaim), so those net VAT costs should be reflected in your quoted prices to protect your margin.