Use revenue after the chosen discount.
Revenue = entered price − customer discount. This model uses values before separately collected taxes. Do not include a tax amount as business earnings or ask the tool to choose a tax treatment.
Operating costs use the entered labour and other-cost totals. Payment fees are then calculated on discounted revenue, plus any fixed fee.
Compare margin and markup using different bases.
Profit = revenue − operating costs − payment fees. Margin = profit ÷ revenue ×100. Markup = profit ÷ total included costs, including fees, ×100.
The same£20 profit is20% of £100 revenue but25% of £80 costs. A zero denominator is shown as not available, not a manufactured0% result.
Make a loss and missing costs visible.
If revenue is £70 and total costs are £80, the scenario loses £10. A negative result is arithmetic feedback; the tool does not guarantee a better price will be accepted or a job will be profitable.
Unentered overhead, owner time or equipment allocations can change the outcome. Review your cost list rather than assuming the displayed profit is take-home pay.
Use the target price as a separate comparison.
The target price solves for the entered costs, payment-fee percentage and desired margin. It is before any discount; the current job result still uses the discount you entered.
For a different question—what is the cost-led floor before you have a customer price?—use the minimum job price tool.
Check the denominators with JavaScript off.
The worksheet and example remain visible. Subtract your costs from revenue, then divide by revenue for margin or by total costs for markup. Leave a ratio undefined if its denominator is zero.
Illustrative arithmetic / not market rates
£100 revenue and£80 costs
Entered price£100, no discount; labour£50 and other costs£30; no fees/taxes. These are illustrative totals.
Declared scenario
EXAMPLE ONLY- Revenue
- £100.00
- Included costs
- £80.00
- Profit
- £20.00
- Margin:£20 ÷£100
- 20.00%
- Markup:£20 ÷£80
- 25.00%
At£70 revenue with the same£80 costs, profit is−£10, margin−14.29% and markup−12.50%. At zero revenue margin is undefined; at zero costs markup is undefined.
Scenario record checked . Read the formula and scenario register.
Review the assumptions
A checklist for this page
- Use customer revenue after discount.
- Include the labour and overhead categories relevant to your scenario.
- Separate tax from the entered revenue/cost assumptions.
- Read the margin and markup denominators before comparing percentages.
Job profit & margin: questions
Is profit the same as my wages?
Not in this model when labour is included as a cost. Profit is the remaining revenue after the costs and fees you entered.
Can the calculator show a negative result?
Yes. When included costs exceed revenue, the result is a loss, with negative ratios where the denominators are positive.
What happens at zero revenue or zero cost?
Profit can still be calculated, but the affected percentage ratio is unavailable. The output explains that it has a zero denominator.
Does a 20% markup mean a 20% margin?
No. Markup uses costs as its denominator; margin uses revenue. The£100/£80 example demonstrates the difference.
Sources and evidence limits
- WashTally formula and scenario register v1.0.0
Declared arithmetic and explicitly hypothetical scenarios checked by automated tests. No trade certification or representative market rates.
Record checked:
A source record or passing arithmetic test does not establish a universal rate, professional review, property assessment or guaranteed outcome.