Retainer Pricing Planner methodology

deliveryCost = included hours × loaded cost + monthly overhead

protectedDeliveryCost = delivery cost ÷ (1 − scope buffer)

monthlyFee = protected delivery cost ÷ (1 − target margin)

annualFee = monthly fee × 12

includedCapacityHours = included hours

productiveCapacityHours = monthly capacity × utilisation

overageRate = loaded cost ÷ (1 − overage target margin)

overageRevenue = overage hours × overage rate

totalRevenue = monthly fee + overage revenue

margin = (total revenue − total cost) ÷ total revenue

remainingCapacityHours = productive capacity − included − overage hours

Money inputs and outputs use the currency selected in the scenario without changing the canonical methodology. Rates, margins, utilisation and buffers are entered as percentages and converted to decimal values for calculation.

• Inputs must be finite and remain within the visible boundaries.
• Rates are decimal values and all monetary inputs use one consistent currency and period.
• Whole operational capacity is rounded only where the engine explicitly applies floor or ceiling.
• The scope buffer grosses delivery cost up by dividing by one minus the buffer rate before the target-margin gross-up.

Included hours minimum

includedHours ≥ 0 hours/month — A lower value is rejected before calculation.

Included hours maximum

includedHours ≤ 10,000,000 hours/month — A higher value is rejected before calculation.

Loaded cost per hour minimum

loadedCostPerHour ≥ 0 currency units/hour — A lower value is rejected before calculation.

Loaded cost per hour maximum

loadedCostPerHour ≤ 10,000,000 currency units/hour — A higher value is rejected before calculation.

Monthly overhead minimum

monthlyOverhead ≥ 0 currency units/month — A lower value is rejected before calculation.

Monthly overhead maximum

monthlyOverhead ≤ 10,000,000 currency units/month — A higher value is rejected before calculation.

Productive utilisation minimum

utilisation ≥ 0 proportion of available retainer capacity billable — A lower value is rejected before calculation.

Productive utilisation maximum

utilisation ≤ 0.99 proportion of available retainer capacity billable — A higher value is rejected before calculation.

Scope buffer minimum

scopeBufferRate ≥ 0 proportion of delivery cost added as scope buffer — A lower value is rejected before calculation.

Scope buffer maximum

scopeBufferRate ≤ 0.99 proportion of delivery cost added as scope buffer — A higher value is rejected before calculation.

Target margin minimum

targetMargin ≥ 0 proportion of client price retained as contribution — A lower value is rejected before calculation.

Target margin maximum

targetMargin ≤ 0.99 proportion of client price retained as contribution — A higher value is rejected before calculation.

Expected overage hours minimum

overageHours ≥ 0 hours/month — A lower value is rejected before calculation.

Expected overage hours maximum

overageHours ≤ 10,000,000 hours/month — A higher value is rejected before calculation.

Overage target margin minimum

overageTargetMargin ≥ 0 proportion of overage price retained as contribution — A lower value is rejected before calculation.

Overage target margin maximum

overageTargetMargin ≤ 0.99 proportion of overage price retained as contribution — A higher value is rejected before calculation.

Monthly capacity hours minimum

monthlyCapacityHours ≥ 0 hours/month — A lower value is rejected before calculation.

Monthly capacity hours maximum

monthlyCapacityHours ≤ 10,000,000 hours/month — A higher value is rejected before calculation.

• All costs, prices, hours, probabilities and volumes are user-supplied; no market benchmark is inferred.
• Tax is outside these neutral commercial comparisons.
• The engine retains full precision; formatting never feeds back into calculation.

This planner has no current policy-data dependency. Its commercial assumptions are user supplied. Registered family-level regression suites exercise the shared business-logic engine and worked-result reconciliation.

• The model does not predict demand, delivery performance, contract enforceability or customer behaviour.
• It does not replace accounting, tax, legal or financial advice.

This is educational decision support, not tax, accounting, legal or financial advice. Check the treatment of your actual transactions under the rules that apply to your business and seek qualified advice where appropriate.

Registered family-level suites test formula invariants and example reconciliation; the release ledger records that coverage without claiming a separate oracle for every line of public copy. There is no official threshold or benchmark to refresh for this planner. Commercial inputs remain user-supplied because they vary by business and contract.

1. 2026-07-31: Initial public release of the planner and methodology after pre-launch calculation, content, source and interaction review.