Retainer Scope & Overage Calculator
Model a retainer package with included hours, rollover, tiered overage, admin time, effective rate, and renewal fee scenarios.
Retainer Scope Inputs
Model the package mechanics without drafting legal terms.
Monthly revenue
£3,770
Effective rate is £77 per internal hour after 7 overage hours and 49 total delivery plus admin hours.
Included + rollover
39 h
Unused included time
0 h
Total overage
7 h
Tier 1 / tier 2
7 h / 0 h
Overage revenue
£770
Included-hour rate
£86
Effective internal rate
£77
Renewal fee scenario
£3,240
When a simple retainer comparison is not enough
The retainer vs hourly calculator compares a flat monthly fee with expected hourly billing. This calculator goes deeper into the retainer package itself.
Use it when you need to model included hours, rollover credit, tiered overage rates, actual usage, internal admin time, and a renewal uplift. Those details decide whether the retainer stays profitable after the client starts using the package.
Worked example: £3,000 retainer, 35 included hours, 46 actual hours
A £3,000 monthly retainer with 35 included hours and 4 rollover hours gives 39 hours before overage. If the client uses 46 hours, the overage is 7 hours.
At £110/hour for the first overage tier, overage revenue is £770, so total monthly revenue becomes £3,770. If internal account admin adds 3 hours, the effective internal rate is about £77/hour across 49 total hours.
That effective rate may be much lower than the apparent included-hour rate, which is why admin load and actual usage should be visible before renewal conversations.
Rollover, caps, and tiered overage
Rollover can make a retainer feel fair, but uncapped rollover can quietly turn one light month into a heavy future month with no extra revenue. The rollover cap field keeps the usable carried hours explicit.
Tiered overage lets you charge one rate for a small excess and a higher rate after a threshold. That can reflect scheduling pressure, rush work, or the opportunity cost of pushing other client work aside.
The calculator treats these as pricing assumptions only. It does not draft terms, enforce contract language, or decide what a client must accept.
Using the result at renewal
Track actual client hours and internal account time for at least a few months before renewal. If effective rate falls below your pricing floor, the package needs a fee increase, tighter scope, fewer included hours, or clearer overage handling.
Use the renewal uplift field to test a future monthly fee. Then compare that result with what should I charge, hourly rate, and timesheet utilisation outputs.
Before You Rely on It
This calculator is a commercial planning tool. It does not provide legal advice, draft contract clauses, interpret service-level obligations, enforce payment terms, or decide whether rollover is legally binding.
Before using the numbers in a contract or renewal, check the actual client relationship, delivery capacity, payment risk, scope definition, and any professional advice you need for the agreement.
Model retainer scope and overage
- 1
Enter the monthly fee and included hours
Start with the core retainer package before rollover or overage.
- 2
Add actual usage and rollover
Enter actual client hours, carried hours available, and the rollover cap you want to apply.
- 3
Set overage tiers
Add the first overage tier size, tier-one rate, and tier-two rate for excess hours beyond the included package.
- 4
Include internal admin time
Add account management, reporting, and coordination time so effective internal rate is honest.
- 5
Review renewal scenario
Use the uplift field to test a future monthly fee before a renewal conversation.
Retainer scope and overage: common questions
What is retainer overage?
Overage is work beyond the included package, usually measured in hours or deliverables and billed at an extra rate.
Why include admin time?
Account management, reporting, and coordination use capacity even when they are not visible as client delivery. Including them makes the effective internal rate more realistic.
Should unused hours roll over?
That is a commercial choice. The calculator lets you model rollover and a cap, but it does not decide contract wording.
How is effective rate calculated?
Total monthly revenue divided by actual client hours plus internal admin hours.
Is this legal advice?
No. It is pricing arithmetic for planning. Contract terms should be checked separately before signing.
Disclaimer: This calculator is for general business planning and education. It does not provide tax, legal, accounting, or investment advice. Check important decisions against real financial records and qualified professionals where appropriate.