The order changes the eligible base
USD 1,000, 10% and USD 100: percentage then fixed leaves USD 800; fixed then percentage leaves USD 810 because the percentage base is USD 900. Difference USD 10.
Invoice totals
Free Invoice Discount Order Calculator
Two approved discount types can produce different totals when their order changes. Compare a fixed amount and percentage on one eligible before-tax subtotal without assuming both are authorized or apply to every line.
What you can do here
Compare percentage-then-fixed and fixed-then-percentage discounts on the same eligible subtotal, showing their different bases and final amounts.
Built for real invoice workflows
Record the approved eligibility and order before adding discounts to a reviewed invoice.
Preparing your calculator with today’s date…
Calculation notes
How the result is calculated
Percentage-first deduction = subtotal × percentage, rounded to cents; subtract that and the fixed amount. Fixed-first deducts the fixed amount, then rounds the percentage deduction on the remainder. Fixed must fit after the percentage-first deduction so neither scenario is negative. Difference = fixed-first final amount − percentage-first final amount. This compares operations, not discount eligibility or approval.
Formulas and examples reviewed October 2, 2026. Illustrative figures; no tax or contractual determination.
A single discount has no order difference
With a zero fixed deduction, both orders apply the entered percentage to the same subtotal and produce the same result. That does not approve the rate or decide tax treatment.
Questions about this calculation
Should I always choose the lower total?
No. Use the authorized order and eligible scope. This comparison makes an operation difference visible, rather than choosing commercial terms.
Does this apply a discount after payment?
No. It compares pre-issue subtotal operations. An already-issued invoice adjustment needs the actual approved correction process.
Sources and further reading
How to use it
1
Enter the eligible subtotal and proposed percentage and fixed discounts.
2
Keep the fixed amount within the subtotal remaining after the percentage step.
3
Compare both orders and use only the order supported by the actual agreement and billing process.
Why it helps
Show each percentage deduction's actual base.
Explain a mismatch caused by operation order.
Keep discount approval and tax treatment separate from the comparison.
Next step
From free tool to live invoice workflow.
Use the result when creating your invoice in InvoiceAgent. Planner setup links carry the settings they describe into a draft. Review your dates, amounts, PDF, and reminder settings before scheduling.
Related workflows
Move from the quick answer into the rest of the invoice system.
Record eligibility and operation order
Record eligibility and operation order
Keep discount scope and decision evidence together.
Review stacked discount bases
Review stacked discount bases
Compare the operation with the approved document.
Invoice templates
Invoice templates
Use the result inside invoice formats that are ready for clients and easier to automate.
Knowledge base
Knowledge base
Review the billing concepts behind the numbers before they go onto a live invoice.
Profession pages
Profession pages
See how freelancers, consultants, and agencies apply the same calculator output in different workflows.