THE NUMBERS, EXPLAINED
How to use this calculator.
Milestone day offsets and contract percentages are supplied. Payments are allocated explicitly, with no implied legal late-fee rule.
Start with your inputs
Enter supplier contract total (currency), milestone installment percentages, payments against each milestone (currency), days from today until each milestone. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Supplier contract total (currency) | 2000 |
| Milestone installment percentages | 25,50,25 |
| Payments against each milestone (currency) | 500,600,0 |
| Days from today until each milestone | 0,30,60 |
A worked example
With the example inputs above, milestone amounts due (currency) is 500, 1000, 500. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Milestone amounts due (currency) | 500, 1000, 500 |
| Unpaid amounts by milestone (currency) | 0, 400, 500 |
| Total unpaid balance (currency) | 900 |
| Currently due unpaid amount (currency) | 0 |
How this is calculated
Milestone amounts due (currency)
Allocate contract value by supplied installment percentages.
Unpaid amounts by milestone (currency)
Deduct payments assigned to each milestone.
Total unpaid balance (currency)
Subtract all payments from contract total.
Currently due unpaid amount (currency)
Include unpaid milestones on or before today.
Symbols and units
- a
- Supplier contract total (currency)
- b
- Milestone installment percentages
- c
- Payments against each milestone (currency)
- d
- Days from today until each milestone
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
Milestone day offsets and contract percentages are supplied. Payments are allocated explicitly, with no implied legal late-fee rule.
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?
Milestone amounts due (currency); Unpaid amounts by milestone (currency); Total unpaid balance (currency); Currently due unpaid amount (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: Milestone day offsets and contract percentages are supplied. Payments are allocated explicitly, with no implied legal late-fee rule.
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 →