THE NUMBERS, EXPLAINED
How to use this calculator.
Visitor and donor counts use a consistent unique-person basis over the same period; excludes processing fees.
Start with your inputs
Enter visitors in reporting period, distinct donors, total donation receipts (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Visitors in reporting period | 1000 |
| Distinct donors | 100 |
| Total donation receipts (currency) | 500 |
A worked example
With the example inputs above, donation uptake (%) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Donation uptake (%) | 10 |
| Donation value per visitor (currency) | 0.5 |
| Average donation per donor (currency) | 5 |
How this is calculated
Donation uptake (%)
Divide unique donors by visitors.
Donation value per visitor (currency)
Divide donation receipts by all visitors.
Average donation per donor (currency)
Divide receipts by distinct donors; zero when there are none.
Symbols and units
- a
- Visitors in reporting period
- b
- Distinct donors
- c
- Total donation receipts (currency)
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
Visitor and donor counts use a consistent unique-person basis over the same period; excludes processing fees.
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?
Donation uptake (%); Donation value per visitor (currency); Average donation per donor (currency). 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: Visitor and donor counts use a consistent unique-person basis over the same period; excludes processing fees.
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: Describe and Identify Cost Drivers ↗
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 →