Most contractors quote based on gut feel. They know their hourly rate and materials cost, but the job profit calculator below reveals the costs that quietly eat your margin — admin time, overhead, and the minutes nobody charges for.
Why your profit per job is lower than you think
A plumber charging R450/hour for a 3-hour job sees R1,350 in revenue. But subtract materials (R800), travel (R200), 45 minutes of admin at R450/hour (R337), and 15% overhead (R203), and the actual profit is R210 — a 15.6% margin. That is the reality for most South African contractors who have never done the full calculation.
The single biggest hidden cost is admin time. Scheduling the job, filling in the job card, creating the invoice, chasing payment, and reporting to the insurer takes anywhere from 30 to 90 minutes per job. At R450/hour, 45 minutes of admin per job across 40 jobs a month costs R13,500 in unbilled time every month — R162,000 per year.
Use the calculator below
Adjust the sliders to match your actual situation. The calculator shows your revenue per job, true costs (including admin), profit, margin, and the annual impact across your full job volume. It also shows what your "true" hourly rate works out to after all hidden costs are factored in.
The three levers that improve job profit
Once you know your real margin, there are three places to improve it. The first is pricing — use this calculator before quoting to make sure your rate actually covers all costs. The second is admin efficiency — every minute saved on job cards, scheduling and invoicing goes straight back into your margin. The third is comebacks — a single return visit to fix a problem can wipe out the profit from two or three completed jobs.
Admin is the fastest win
Unlike materials cost (fixed by suppliers) or hourly rates (constrained by what the market will pay), admin time is entirely within your control. Contractors using PlanMyCrew typically reduce admin time per job from 45 minutes to under 10 — saving over R120,000 per year on a volume of 40 jobs per month at R450/hour.
That saving does not require raising prices or winning more work. It just requires automating the tasks you are currently doing manually.
Insurance field contractors: the margin squeeze is real
If you are on an insurance panel, your job rates are largely fixed by the insurer. That means the only way to improve margin is to reduce costs — and admin is the biggest controllable cost. Panel contractors who automate job parsing, job cards, SLA tracking and invoicing consistently report 20–30% improvement in effective job margin without changing their panel rates at all.