THE NUMBERS, EXPLAINED
How to use this calculator.
Task ranges are entered bounds, not statistical confidence intervals. All added effort is sequentially scheduled after existing scope.
Start with your inputs
Enter additional task low estimates (hours), additional task high estimates (hours), hourly billing rate (currency), existing accepted quote (currency), daily available project hours. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Additional task low estimates (hours) | 2,3 |
| Additional task high estimates (hours) | 4,5 |
| Hourly billing rate (currency) | 100 |
| Existing accepted quote (currency) | 2000 |
| Daily available project hours | 4 |
A worked example
With the example inputs above, revised low quote (currency) is 2,500. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Revised low quote (currency) | 2,500 |
| Revised high quote (currency) | 2,900 |
| Additional low workdays | 1.25 |
| Additional high workdays | 2.25 |
How this is calculated
Revised low quote (currency)
Add low additional effort at the entered billing rate.
Revised high quote (currency)
Add high additional effort at the same rate.
Additional low workdays
Divide low effort by available project hours per day.
Additional high workdays
Divide high effort by daily project availability.
Symbols and units
- a
- Additional task low estimates (hours)
- b
- Additional task high estimates (hours)
- c
- Hourly billing rate (currency)
- d
- Existing accepted quote (currency)
- e
- Daily available project hours
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
Task ranges are entered bounds, not statistical confidence intervals. All added effort is sequentially scheduled after existing scope.
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?
Revised low quote (currency); Revised high quote (currency); Additional low workdays; Additional high workdays. 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: Task ranges are entered bounds, not statistical confidence intervals. All added effort is sequentially scheduled after existing scope.
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 →