How to Track Job Costs as a Solo Contractor
February 2026 · 6 min read
Most solo contractors know their revenue. Few know their actual profit per job. The difference between a $50K year and a $120K year often comes down to one thing: knowing your numbers. Here's a simple job costing system that works without expensive software.
Why Job Costing Matters
Without job costing, you're guessing. You might bid a kitchen rewire at $3,500 thinking you'll make $1,500 profit — but between that extra trip to the supply house, the two hours troubleshooting the old panel, and the $200 in wire you didn't account for, your actual profit was $600.
Do that five times a month and you've left $54,000 on the table annually.
The Four Cost Categories
1. Materials
Everything you buy for the job: wire, boxes, breakers, connectors, fixtures. Track receipts by job. The easiest place to start.
- Save every receipt (photo it immediately — paper fades)
- Tag each purchase to a specific job
- Track supply house returns and credits
2. Direct Labor
Your hours and any crew you hire. Be honest with yourself — track actual hours, not what you bid.
- Clock in and out per job, including drive time
- Track helper/apprentice hours separately at their rate
- Include time spent on callbacks and punch lists
3. Overhead
The costs that exist whether you're working or not: truck payment, insurance, tools, license fees, phone, fuel. Calculate your monthly overhead, divide by working hours, and apply it as an hourly rate.
Example: $3,000/month overhead ÷ 160 billable hours = $18.75/hour overhead rate. A 20-hour job carries $375 in overhead.
4. Profit
What's left after materials + labor + overhead. This is your actual take-home from the job. Target 15-25% profit margin after all costs.
The Simple Tracking Method
- Before the job: Create a bid with estimated materials, labor hours, overhead, and target profit. Use our free Contractor Bid Calculator to build quick estimates.
- During the job: Track actual time with a timer app (Stats JobClock logs per job automatically). Photo receipts immediately.
- After the job: Compare actual costs to your bid. Calculate real profit. Note what you missed.
- Monthly review: Which jobs made money? Which didn't? Adjust your bids accordingly.
The Key Insight
After tracking 20-30 jobs, you'll discover patterns: certain job types consistently make money, others consistently don't. Some clients generate callbacks, others don't. Some supply houses are cheaper for specific materials.
This data is worth thousands per year in better bidding. The contractors who track this stuff grow. The ones who don't stay stuck.
Tools That Help
- ContractorQuote — Build accurate bids with material + labor + overhead + profit
- Stats JobClock — Track time per job with GPS verification
- Free Bid Calculator — Quick estimates in your browser