THE NUMBERS, EXPLAINED
How to use this calculator.
Single percentage coupon; threshold tests eligible subtotal before discount. Excluded items never count toward the threshold. No stacking or taxes.
Start with your inputs
Enter eligible item subtotal, excluded item subtotal, required eligible spend, coupon rate (%), discount cap. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Eligible item subtotal | 80 |
| Excluded item subtotal | 20 |
| Required eligible spend | 50 |
| Coupon rate (%) | 25 |
| Discount cap | 15 |
A worked example
With the example inputs above, coupon qualifies is Yes. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Coupon qualifies | Yes |
| Discount | 15 |
| Final basket | 85 |
How this is calculated
Coupon qualifies
Compare eligible subtotal with the stated threshold.
Discount
If eligible, apply percentage discount capped at the supplied limit.
Final basket
Subtract discount from all item subtotals.
Symbols and units
- a
- Eligible item subtotal
- b
- Excluded item subtotal
- c
- Required eligible spend
- d
- Coupon rate (%)
- e
- Discount cap
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
Single percentage coupon; threshold tests eligible subtotal before discount. Excluded items never count toward the threshold. No stacking or taxes.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Coupon qualifies; Discount; Final basket. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Single percentage coupon; threshold tests eligible subtotal before discount. Excluded items never count toward the threshold. No stacking or taxes.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: Solve proportions and their applications ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →