THE NUMBERS, EXPLAINED
How to use this calculator.
Rollover amounts must already reflect each contract cap and expiry rule. Reserved hours are counted even if clients may not use them.
Start with your inputs
Enter retainer included hours by client, approved rollover hours by client, available delivery hours this period, hours already used by client. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Retainer included hours by client | 20,30 |
| Approved rollover hours by client | 5,10 |
| Available delivery hours this period | 60 |
| Hours already used by client | 10,15 |
A worked example
With the example inputs above, total period entitlement (hours) is 65. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Total period entitlement (hours) | 65 |
| Remaining client entitlements (hours) | 15, 25 |
| Remaining delivery capacity (hours) | 35 |
| Overcommitted period capacity (hours) | 5 |
How this is calculated
Total period entitlement (hours)
Add included and approved rollover hours.
Remaining client entitlements (hours)
Subtract used hours from each client entitlement.
Remaining delivery capacity (hours)
Deduct work already delivered from period availability.
Overcommitted period capacity (hours)
Compare total reserved entitlement with delivery hours.
Symbols and units
- a
- Retainer included hours by client
- b
- Approved rollover hours by client
- c
- Available delivery hours this period
- d
- Hours already used by client
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
Rollover amounts must already reflect each contract cap and expiry rule. Reserved hours are counted even if clients may not use them.
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?
Total period entitlement (hours); Remaining client entitlements (hours); Remaining delivery capacity (hours); Overcommitted period capacity (hours). 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: Rollover amounts must already reflect each contract cap and expiry rule. Reserved hours are counted even if clients may not use them.
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 →