Methodology
Gross to Operating Profit Bridge methodology
Identify which operating-cost layer changes profit after gross profit, then compare a revised scenario with the target.
Educational only: Business decision support, not accounting, tax or legal advice.
Privacy: Calculations run locally; Margin101 does not receive your commercial inputs.
Update policy: Reviewed when formulas or official dependencies change.
Scope: Market-neutral small-business planning using your own assumptions.
1. Formulas and units
baselineGrossProfitExTax = revenue − cost of salesWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- costOfSalesExTax
- Cost of sales (currency units/period)Source: Business record
- baselineGrossProfitExTax
- Baseline Gross Profit Ex Tax (currency units, ex tax)Source: Calculated output
baselineGrossMargin = baseline gross profit ÷ baseline revenueWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- baselineGrossProfitExTax
- Baseline Gross Profit Ex Tax (currency units, ex tax)Source: Calculated output
- baselineGrossMargin
- Baseline Gross Margin (decimal rate)Source: Calculated output
baselineOperatingCostsExTax = labour + occupancy + sales and marketing + admin and other costsWhere
- labourOperatingCostsExTax
- Labour operating costs (currency units/period)Source: Business record
- occupancyOperatingCostsExTax
- Occupancy operating costs (currency units/period)Source: Business record
- salesAndMarketingOperatingCostsExTax
- Sales and marketing costs (currency units/period)Source: Business record
- adminAndOtherOperatingCostsExTax
- Admin and other costs (currency units/period)Source: Business record
- baselineOperatingCostsExTax
- Baseline Operating Costs Ex Tax (currency units, ex tax)Source: Calculated output
baselineOperatingProfitExTax = baseline gross profit − baseline operating costsWhere
- baselineGrossProfitExTax
- Baseline Gross Profit Ex Tax (currency units, ex tax)Source: Calculated output
- baselineOperatingCostsExTax
- Baseline Operating Costs Ex Tax (currency units, ex tax)Source: Calculated output
- baselineOperatingProfitExTax
- Baseline Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
baselineOperatingMargin = baseline operating profit ÷ baseline revenueWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- baselineOperatingProfitExTax
- Baseline Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- baselineOperatingMargin
- Baseline Operating Margin (decimal rate)Source: Calculated output
baselineTargetGapExTax = baseline operating profit − target profitWhere
- targetOperatingProfitExTax
- Target operating profit (currency units/period)Source: User decision
- baselineOperatingProfitExTax
- Baseline Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- baselineTargetGapExTax
- Baseline Target Gap Ex Tax (currency units, ex tax)Source: Calculated output
revisedRevenueExTax = revenue × (1 + revenue change)Where
- revenueExTax
- Revenue (currency units/period)Source: Business record
- revenueChangeRate
- Revenue change (proportional change in revenue versus baseline)Source: User assumption
- revisedRevenueExTax
- Revised Revenue Ex Tax (currency units, ex tax)Source: Calculated output
revisedCostOfSalesExTax = cost of sales × (1 + cost-of-sales change)Where
- costOfSalesExTax
- Cost of sales (currency units/period)Source: Business record
- costOfSalesChangeRate
- Cost-of-sales change (proportional change in cost of sales versus baseline)Source: User assumption
- revisedCostOfSalesExTax
- Revised Cost Of Sales Ex Tax (currency units, ex tax)Source: Calculated output
revisedGrossProfitExTax = revised revenue − revised cost of salesWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- costOfSalesExTax
- Cost of sales (currency units/period)Source: Business record
- revisedRevenueExTax
- Revised Revenue Ex Tax (currency units, ex tax)Source: Calculated output
- revisedCostOfSalesExTax
- Revised Cost Of Sales Ex Tax (currency units, ex tax)Source: Calculated output
- revisedGrossProfitExTax
- Revised Gross Profit Ex Tax (currency units, ex tax)Source: Calculated output
revisedOperatingCostsExTax = sum of revised operating-cost layersWhere
- revisedOperatingCostsExTax
- Revised Operating Costs Ex Tax (currency units, ex tax)Source: Calculated output
revisedOperatingProfitExTax = revised gross profit − revised operating costsWhere
- revisedGrossProfitExTax
- Revised Gross Profit Ex Tax (currency units, ex tax)Source: Calculated output
- revisedOperatingCostsExTax
- Revised Operating Costs Ex Tax (currency units, ex tax)Source: Calculated output
- revisedOperatingProfitExTax
- Revised Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
revisedOperatingMargin = revised operating profit ÷ revised revenueWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- revisedRevenueExTax
- Revised Revenue Ex Tax (currency units, ex tax)Source: Calculated output
- revisedOperatingProfitExTax
- Revised Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- revisedOperatingMargin
- Revised Operating Margin (decimal rate)Source: Calculated output
revisedTargetGapExTax = revised operating profit − target profitWhere
- targetOperatingProfitExTax
- Target operating profit (currency units/period)Source: User decision
- revisedOperatingProfitExTax
- Revised Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- revisedTargetGapExTax
- Revised Target Gap Ex Tax (currency units, ex tax)Source: Calculated output
operatingProfitDeltaExTax = revised operating profit − baseline operating profitWhere
- baselineOperatingProfitExTax
- Baseline Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- revisedOperatingProfitExTax
- Revised Operating Profit Ex Tax (currency units, ex tax)Source: Calculated output
- operatingProfitDeltaExTax
- Operating Profit Delta Ex Tax (currency units, ex tax)Source: Calculated output
revenueEffectExTax = revised revenue − baseline revenueWhere
- revenueExTax
- Revenue (currency units/period)Source: Business record
- revisedRevenueExTax
- Revised Revenue Ex Tax (currency units, ex tax)Source: Calculated output
- revenueEffectExTax
- Revenue Effect Ex Tax (currency units, ex tax)Source: Calculated output
costOfSalesEffectExTax = −(revised cost of sales − baseline cost of sales)Where
- costOfSalesExTax
- Cost of sales (currency units/period)Source: Business record
- revisedCostOfSalesExTax
- Revised Cost Of Sales Ex Tax (currency units, ex tax)Source: Calculated output
- costOfSalesEffectExTax
- Cost Of Sales Effect Ex Tax (currency units, ex tax)Source: Calculated output
labourCostEffectExTax = −(revised labour cost − baseline labour cost)Where
- labourCostEffectExTax
- Labour Cost Effect Ex Tax (currency units, ex tax)Source: Calculated output
occupancyCostEffectExTax = −(revised occupancy cost − baseline occupancy cost)Where
- occupancyCostEffectExTax
- Occupancy Cost Effect Ex Tax (currency units, ex tax)Source: Calculated output
salesAndMarketingCostEffectExTax = −(revised sales and marketing cost − baseline cost)Where
- costOfSalesExTax
- Cost of sales (currency units/period)Source: Business record
- revisedCostOfSalesExTax
- Revised Cost Of Sales Ex Tax (currency units, ex tax)Source: Calculated output
- costOfSalesEffectExTax
- Cost Of Sales Effect Ex Tax (currency units, ex tax)Source: Calculated output
- salesAndMarketingCostEffectExTax
- Sales And Marketing Cost Effect Ex Tax (currency units, ex tax)Source: Calculated output
adminAndOtherCostEffectExTax = −(revised admin and other cost − baseline cost)Where
- adminAndOtherCostEffectExTax
- Admin And Other Cost Effect Ex Tax (currency units, ex tax)Source: Calculated output
bridgeReconciliationExTax = sum of signed effects − operating-profit deltaWhere
- operatingProfitDeltaExTax
- Operating Profit Delta Ex Tax (currency units, ex tax)Source: Calculated output
- bridgeReconciliationExTax
- Bridge Reconciliation Ex Tax (currency units, ex tax)Source: Calculated output
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.
2. Worked example
Input assumptions
The worked rows below come directly from the registered engine and visible default fixture.
Calculation and outputs
Example
The worked rows below come directly from the registered engine and visible default fixture.
- Baseline Gross Profit Ex Tax
- 45,000 currency units
- Baseline Gross Margin
- 45%
- Baseline Operating Costs Ex Tax
- 25,000 currency units
- Baseline Operating Profit Ex Tax
- 20,000 currency units
- Baseline Operating Margin
- 20%
- Baseline Target Gap Ex Tax
- -2,000 currency units
- Revised Revenue Ex Tax
- 105,000 currency units
- Revised Cost Of Sales Ex Tax
- 56,100 currency units
- Revised Gross Profit Ex Tax
- 48,900 currency units
- Revised Operating Costs Ex Tax
- 24,700 currency units
- Revised Operating Profit Ex Tax
- 24,200 currency units
- Revised Operating Margin
- 23%
- Revised Target Gap Ex Tax
- 2,200 currency units
- Operating Profit Delta Ex Tax
- 4,200 currency units
- Revenue Effect Ex Tax
- 5,000 currency units
- Cost Of Sales Effect Ex Tax
- -1,100 currency units
- Labour Cost Effect Ex Tax
- 600 currency units
- Occupancy Cost Effect Ex Tax
- 0 currency units
- Sales And Marketing Cost Effect Ex Tax
- -300 currency units
- Admin And Other Cost Effect Ex Tax
- 0 currency units
- Bridge Reconciliation Ex Tax
- 0 currency units
The exact engine-derived outputs are shown in the labelled rows below.
Interpretation
The bridge reconciles the entered revenue and cost changes to operating profit without inferring accounting classifications.
3. Validation and boundary checks
- All inputs must be finite and within the visible boundaries.
- Costs, revenue and contribution use one consistent ex-tax basis and planning period.
- Whole-unit thresholds round upward only where the named engine formula requires it.
4. Assumptions and source classification
- All prices, costs, demand limits and capacity values are user-supplied records or explicit scenarios.
- Allocated costs remain visible and separate from avoidable costs.
- The global workflow infers no market benchmark, policy threshold or future demand.
This diagnostic 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.
5. Limitations
- This planning bridge stops at operating profit. It excludes finance costs, tax, cash timing and accounting classification.
- The model does not forecast demand, implementation timing, service quality or strategic fit.
- 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.
6. Update and evidence policy
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 diagnostic. Commercial inputs remain user-supplied because they vary by business and contract.
Change history
- : Initial public release of the planner and methodology after pre-launch calculation, content, source and interaction review.
Related reading
Guides to interpret the decision and its assumptions.
- Where Did the Margin Go? A Margin-Compression Diagnostic
Reconcile price, mix, cost, waste, fee and allocation effects before choosing an action, while keeping residuals and causation limits visible.
Read guide - Cost Creep: Catch Small Changes Before They Hurt Margin
Bridge comparable periods into rate, quantity, mix, waste, fee and allocation effects before assigning action and review triggers.
Read guide